Definition from Wiktionary, the free dictionary
nonplus (plural nonpluses)
- A state of perplexity or bewilderment.
- altering Vaudemont, to Vallemontanus, and metamorphosing them, by suting them to the Græcian or Latin tongue, we know not what to make of them, and are often at a non-plus.
- Both of them are a perfect nonplus and baffle to all human understanding.