nix(noun, verb) noun1. a quantity of no importanceSimilar word(s): aught, cipher, cypher, nada, naught, nil, nothing, null, zero, zilch, zip, zippoDefinition categories: quantity verb1. command against- Dad nixed our plansSimilar word(s): disallow, forbid, interdict, prohibit, proscribe, vetoDefinition categories: communication, command, requireSentences with nix as a verb:- Nix the last order - the customer walked out.