non-

UK: /ˈnɒn-/

WordReference Random House Learner's Dictionary of American English © 2025

non-, prefix. 

1. non-, usually meaning "not,'' is attached
   • to adjectives and adverbs and means a simple negative or absence of something:
     non- + violent → nonviolent.
   • to a noun of action and means the failure of such action:
     non- + payment → nonpayment (= failure to pay).
   • to a noun to suggest that the thing mentioned is not true, real, or worthy of the name:
     nonevent.

WordReference Random House Unabridged Dictionary of American English © 2025

non-, 

1. a prefix meaning "not,'' freely used as an English formative, usually with a simple negative force as implying mere negation or absence of something (rather than the opposite or reverse of it, as often expressed by un- ¹):
   nonadherence;
   nonpayment;
   nonprofessional.

• prefix representing Latin adverb, adverbial nōn not

Collins Concise English Dictionary © HarperCollins Publishers::

non- prefix

1. indicating negation: nonexistent
2. indicating refusal or failure: noncooperation
3. indicating exclusion from a specified class of persons or things: nonfiction
4. indicating lack or absence, esp of a quality associated with what is specified: nonobjective, nonevent

Etymology: from Latin nōn not