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
verb
nulled; nulling; nulls
Definition of null (Entry 3 of 3)
: to make null
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Merriam-Webster unabridged
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Time Traveler for null
The first known use of null was in 1542
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