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; noninterference; nonpayment; nonprofessional.
prefix meaning "not, lack of," or "sham," 14c., from Anglo-Fr. noun-, from O.Fr. non-, from L. non "not, not a," from Old L. noenum "not one" (*ne oinom). In some cases perhaps from M.E. non "not" (adj.), from O.E. nan (see not).