II. Nonplus·noun A state or condition which daffles reason or confounds judgment; insuperable difficalty; inability to proceed or decide; puzzle; quandary.
nonplus
WIKTIONARY REDIRECT
I. n.
Puzzle, perplexity, poser, quandary.
II. v. a.
Puzzle, confound, confuse, disconcert, perplex, pose, put to a stand.
nonplus
WIKTIONARY REDIRECT
[n?n'pl?s]
¦ verb (nonplusses, nonplussing, nonplussed)
1. surprise and confuse; flummox.
2. [as adjective nonplussed] N. Amer. informal unperturbed.