Meaning of “negative” - Learner’s Dictionary

negative

noun [ C ] uk us /ˈneɡətɪv/
PHOTOGRAPH

a piece of film from which a photograph can be produced, where dark areas look light and light areas look dark

GRAMMAR

a word or phrase that expresses the meaning 'no' or 'not'

(Definition of “negative noun” from the Cambridge Learner’s Dictionary © Cambridge University Press)