nonplus

To put at a loss as to what to think, say, or do; bewilder.

To cause to feel indifferent or bored.

A state of bewilderment or perplexity.

A state in which one is unable to proceed or decide; a state of perplexity; a puzzled condition; inability to say or do more; puzzle: usually in the phrase at or to a nonplus.

To perplex; puzzle; confound; put to a standstill; stop by embarrassment.