Nonplussed

Part of speech: adjective

Pronunciation: /nɒnˈplʌst/

Definitions

1. Unable to proceed or react due to being utterly confused or surprised
2. Caught off guard and unable to respond because of confusion or astonishment
3. In a state of bewilderment that leaves one at a loss for how to act or reply

Etymology: The adjective "nonplussed" grows from a Latin phrase meaning "no further." The Latin "nōn plūs" combined "not" and "more," and the English noun "nonplus" came from it, describing a state where a person has reached the end of what they can say or do. The sense is close to being struck speechless by confusion: there is simply "no more" to offer. The past-tense ending "-ed" was then attached to the noun and verb, turning the word into the adjective we use now. Its root is the Proto-Indo-European "*pleh₁-," meaning "to fill," which also gives us "full" and "plenty." Many speakers today use the word to mean "unaffected" or "unfazed," the opposite of its traditional sense. This second meaning probably arose from a misreading of the opening "non-" as the common prefix meaning "not," as if the word meant "not plussed." The original sense of being thoroughly bewildered remains the standard one.

Synonyms: perplexed, bewildered

Antonyms: unfazed, unperturbed