: to make (something) smaller in size, amount, number, etc.
: to cause (someone) to be in a specified state or condition
: to cause (something) to be in a specified form by breaking it, burning it, etc.
Full Definition of REDUCE
a: to draw together or cause to converge :consolidate<reduce all the questions to one>
b (1): to diminish in size, amount, extent, or number <reduce taxes><reduce the likelihood of war>(2): to decrease the volume and concentrate the flavor of by boiling <add the wine and reduce the sauce for two minutes>
c: to narrow down :restrict<the Indians were reduced to small reservations>
: to correct (as a fracture or a herniated mass) by bringing displaced or broken parts back into their normal positions
a: to bring to the metallic state by removal of nonmetallic elements <reduce an ore by heat>b:deoxidizec: to combine with or subject to the action of hydrogen d (1): to change (an element or ion) from a higher to a lower oxidation state (2): to add one or more electrons to (an atom or ion or molecule)
: to become diminished or lessened; especially: to lose weight by dieting
: to become reduced <ferrous iron reduces to ferric iron>