- without legal force; invalid; (esp in the phrase null and void)
- without value or consequence; useless
- lacking distinction; characterless
- nonexistent; amounting to nothing
- quantitatively zero
- relating to zero
- (of a set) having no members
- involving measurement in which an instrument has a zero reading, as with a Wheatstone bridge
WordReference Random House Learner's Dictionary of American English © 2026
null /nʌl/USA pronunciation
adj.
nul•li•ty, n. [uncountable]See -null-.
-null-, root.
WordReference Random House Unabridged Dictionary of American English © 2026- lacking value or significance.
- being or amounting to nothing;
nil. - Mathematics(of a set)
- empty:A null set is a collection that has no members in it.
- Idioms null and void, without force or effect;
not valid:The contract is now null and void.
nul•li•ty, n. [uncountable]See -null-.
-null-, root.
- -null- comes from Latin, where it has the meaning "none;
not one.'' This meaning is found in such words as: annul, null, nullify.
null
(nul),USA pronunciation adj.
n.
v.t.
- without value, effect, consequence, or significance.
- being or amounting to nothing;
nil;
lacking;
nonexistent. - Mathematics(of a set)
- empty.
- of measure zero.
- being or amounting to zero.
- Idioms null and void, without legal force or effect;
not valid:This contract is null and void.
n.
- Electronicsa point of minimum signal reception, as on a radio direction finder or other electronic meter.
v.t.
- to cancel;
make null.
- Latin nūllus, equivalent. to n(e) not + ūllus any
- 1555–65
Collins Concise English Dictionary © HarperCollins Publishers::
null /nʌl/ adj
'null' also found in these entries (note: many are not synonyms or translations):
abate
- aleph-null
- annul
- defeat
- Kol Nidre
- null hypothesis
- nullity
- power
- unavoidable
- void
- acceptance region
- alternative hypothesis
- critical region
- defeasance
- empty
- nulli-
- null method
- nullo
- null sequence
- null-space
- rejection region
- Type I error
- Type II error
- Wheatstone bridge
- significance level