verb (used with object), non·plussed or non·plused, non·plus·sing or non·plus·ing.
- to render utterly perplexed; puzzle completely.
- a state of utter perplexity.
verb -plusses, -plussing or -plussed or US -pluses, -plusing or -plused
- (tr) to put at a loss; confoundhe was nonplussed by the sudden announcement
noun plural -pluses
- a state of utter perplexity prohibiting action or speech
adj.c.1600, past participle adjective from nonplus. v.“to bring to a nonplus, to perplex,” 1590s, from the noun (1580s), properly “state where ‘nothing more’ can be done or said,” from Latin non plus “no more, no further” (see plus). Related: Nonplussed.