noun, slang ·Moderate ·College level

Definitions

Noun

1. 1
   Something that is forbidden, prohibited, discouraged or taboo. childish, colloquial, often

   "Smoking indoors is becoming a real no-no these days, in many places."

2. 2
   A no-hitter; a game in which no batter on one of the teams got a hit. colloquial

   "He threw two no-nos in his career."

Synonyms

All synonyms

bancontrabandcursecussdenialembargo

Antonyms

All antonyms

must

Example

More examples

"Division by zero is a big no-no in mathematics."

Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.