1
                    
        a
    
          
                                          
              
            
                  —used as a function word to indicate position in contact with and supported by the top surface of
the book is lying on the table
    
                
                    
        b
    
          
                                          
              
            
                  —used as a function word to indicate position in or in contact with an outer surface
the fly landed on the ceiling
I have a cut on my finger
paint on the wall
    
                
                    
        c
    
          
                                          
              
            
                  —used as a function word to indicate position in close proximity with
a village on the sea
stay on your opponent
    
                
                    
        d
    
          
                                          
              
            
                  —used as a function word to indicate the location of something
on the left
on the south side of the house
on the farm
    
                
                    2
                    
        a
    
          
                                          
              
            
                  —used as a function word to indicate a source of attachment or support
on a string
stand on one foot
hang it on a nail
    
                
                    
        b
    
          
                                          
              
            
                  —used as a function word to indicate a source of dependence
you can rely on me
feeds on insects
lives on a pension
    
                
                    
        c
    
          
                                          
              
            
                  —used as a function word to indicate means of conveyance
on the bus
    
                
                    
        d
    
          
                                          
              
            
                  —used as a function word to indicate presence in the possession of
had a knife on him
    
                
                    3
                    
                                          
              
            
                  —used as a function word to indicate a time frame during which something takes place
a parade on Sunday
             or an instant, action, or occurrence when something begins or is doneon cue
on arriving home, I found your letter
news on the hour
cash on delivery
    
                
                    4
                    
                                archaic 
                                  
              
          
                                                      : of                                      
                
                    
5
                    
        a
    
          
                                          
              
            
                  —used as a function word to indicate manner of doing something                  —often used with the
on the sly
keep everything on the up-and-up
    
                
                    
        b
    
          
                                          
              
            
                  —used as a function word to indicate means or agency
cut myself on a knife
talk on the telephone
    
                
                    
        c
    
          
                                          
              
            
                  —used as a function word to indicate a medium of expression
on stage
best show on television
    
                
                    6
                    
        a(1)
    
                
                                          
              
            
                  —used as a function word to indicate active involvement in a condition or status
on the increase
on the lookout
    
                
                    
        (2)
    
          
                                          
              
          
                                                      : regularly using or showing the effects of using                                      
              
                             
on drugs
                         
                
                    
        b
    
          
                                          
              
            
                  —used as a function word to indicate involvement or participation
on tour
on the team
on duty
    
                
                    
        c
    
          
                                          
              
            
                  —used as a function word to indicate inclusion
put it on the agenda
    
                
                    
        d
    
          
                                          
              
            
                  —used as a function word to indicate position or status in proper relationship with a standard or objective
on schedule
    
                
                    7
                    
        a
    
          
                                          
              
            
                  —used as a function word to indicate reason, ground, or basis (as for an action, opinion, or computation)
I have it on good authority
on one condition
the interest will be 10 cents on the dollar
    
                
                    
        b
    
          
                                          
              
            
                  —used as a function word to indicate the cause or source
profited on the sale of stock
    
                
                    
        c
    
          
                                          
              
            
                  —used as a function word to indicate the focus of obligation or responsibility
drinks are on the house
put the blame on me
    
                
                    8
                    
        a
    
          
                                          
              
            
                  —used as a function word to indicate the object of collision, opposition, or hostile action
bumped my head on a limb
an attack on religion
pulled a gun on me
    
                
                    
        b
    
          
                                          
              
            
                  —used as a function word to indicate the object with respect to some disadvantage, handicap, or detriment
has three inches in height on me
a 3-game lead on the second-place team
the joke's on me
    
                
                    9
                    
        a
    
          
                                          
              
            
                  —used as a function word to indicate destination or the focus of some action, movement, or directed effort
crept up on him
feast your eyes on this
working on my skiing
made a payment on the loan
    
                
                    
        b
    
          
                                          
              
            
                  —used as a function word to indicate the focus of feelings, determination, or will
have pity on me
keen on sports
a curse on you
    
                
                    
        c
    
          
                                          
              
            
                  —used as a function word to indicate the object with respect to some misfortune or disadvantageous event
the crops died on them
    
                
                    
        d
    
          
                                          
              
            
                  —used as a function word to indicate the subject of study, discussion, or consideration
a book on insects
reflect on that a moment
agree on price
    
                
                    
        e
    
          
                                          
              
          
                                                      : with respect to                                      
              
                             
go light on the salt
                                       short on cash
                         
                
                    10
                    
                                          
              
            
                  —used as a function word to indicate reduplication or succession in a series
loss on loss
trouble on trouble
    
                
                    1
                    
        a
    
          
                                          
              
          
                                                      : in or into a position of contact with an upper surface especially so as to be positioned for use or operation                                      
              
                             
put the plates on
                         
                
                    
        b
    
          
                                          
              
          
                                                      : in or into a position of being attached to or covering a surface                                      
                
                                
            especially                
          
                                                      : in or into the condition of being worn                                       
              
                             
            put his new shoes on    
                         
            2
                    
        a
    
          
                                          
              
          
                                                      : forward or at a more advanced point in space or time                                      
              
                             
went on home
                                       later on
                         
                
                    
        b
    
          
                                          
              
          
                                                      : in continuance or succession                                      
              
                             
rambled on
                                       and so on
                         
                
                    3
                    
                                          
              
          
                                                      : into operation or a position permitting operation                                      
              
                             
switched the light on
                         
                
                    1
                    
                                          
              
          
                                                      : engaged in an activity or function (such as a dramatic role)                                      
                
                    
2
                    
        a(1)
    
                
                                          
              
          
                                                      : being in operation                                      
              
                             
The radio is on.
                         
                
                    
        (2)
    
          
                                          
              
          
                                                      : placed so as to permit operation                                      
              
                             
The switch is on.
                         
                
                    
        b
    
          
                                          
              
          
                                                      : taking place or being broadcast                                      
              
                             
The game is on.
                         
                
                    3
                    
                                          
              
          
                                                      : aware of something                                      
                
                  —usually used with to
My boss was on to me.
    
                
                    5
                    
                                British 
                                  
              
          
                                                      : talking or harping incessantly                                      
                
                  —used with about
    
                
                    
6
                    
                                chiefly British 
                                  
              
          
                                                      : regarded as possible or feasible                                      
                
                  —usually used in negative constructions
    
                
                    
7
                    
        a
    
          
                                          
              
          
                                                      : engaged in or as if in a performance                                      
              
                             
The comedian was always on.
                         
                
                    
        b
    
          
                                          
              
          
                                                      : being at a high level of performance                                      
                
                    
                                
              
          
                                                      : chemical compound not a ketone or other oxo compound                                      
              
                             
parathion
                         
                
                    1
                    
                                          
              
          
                                                      : subatomic particle                                      
              
                             
nucleon
                         
                
                    2
                    
        a
    
          
                                          
              
          
                                                      : unit : quantum                                      
              
                             
photon
                                       magneton
                         
                
                    
        b
    
          
                                          
              
          
                                                      : basic hereditary component                                      
              
                             
cistron
                                       operon
                         
                
                    
                                
              
          
                                                      : noble gas                                      
              
                             
radon
                         
                
                    Love words? Need even more definitions?
  
  Merriam-Webster unabridged




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