Nonplus \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.