Non"plus (?), n. [L. non not + plus more, further. See Plural.]
A state or condition which daffles reason or confounds judgment; insuperable difficalty; inability to proceed or decide; puzzle; quandary.
Both of them are a perfect nonplus and baffle to all human understanding.
South.
© Webster 1913.
Non"plus` (?), v. t. [imp. & p. p. Nonplused (?) or Nonplussed; p. pr. & vb. n. Nonplusing or Nonplussing.]
To puzzle; to confound; to perplex; to cause to stop by embarrassment.
He has been nonplused by Mr. Dry's desiring him to tell what it was that he endeavored to prove.
Spectator.
© Webster 1913.