Nonplus
Nonplus , noun
[Latin non not + plus more, further. See Plural.]
A state or condition which baffles reason or confounds judgment; insuperable difficulty; inability to proceed or decide; puzzle; quandary.
Both of them are a perfect nonplus and baffle to all human understanding.
Nonplus , transitive verb
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.