Definition of null
(Entry 1 of 3)
1 : having no legal or binding force : invalid a null contract
2 : amounting to nothing : nil the null uselessness of the wireless transmitter that lacks a receiving station— Fred Majdalany
3 : having no value : insignificant … news as null as nothing …— Emily Dickinson
4a : having no elements (see element sense b(3))
null set
b : having zero as a limit
null sequence
c of a matrix : having all elements equal to zero
5a : indicating usually by a zero reading on a scale when a given quantity (such as current or voltage) is zero or when two quantities are equal
—used of an instrument
b : being or relating to a method of measurement in which an unknown quantity (as of electric current) is compared with a known quantity of the same kind and found equal by a null detector
6 : of, being, or relating to zero
The meter gave a null reading.
7 : zero sense 1c
null
nounDefinition of null (Entry 2 of 3)
1 : zero sense 3a(1)
2a : a condition of a radio receiver when minimum or zero signal is received
b : a minimum or zero value of an electric current or of a radio signal
null
verbnulled; nulling; nulls
Definition of null (Entry 3 of 3)
: to make null
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Time Traveler for null
The first known use of null was in 1542
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