# nonplussed

> English word · Adjective · IPA /nɒnˈplʌst/ · frequency rank #82,598

## Definitions
1. Unsure how to act or respond; bewildered, perplexed.
2. Unaffected, unfazed; unimpressed.

## Etymology
From nonplus (“state of bewilderment or perplexity”, noun) or nonplus (“to bewilder or perplex (someone)”, verb) + -ed (suffix forming adjectives, and the past tense and past participle forms of verbs). Nonplus (noun) is derived from Latin nōn plūs (“no further, no more”), from nōn (“not”) + plūs (“additionally, more; further”) (ultimately from Proto-Indo-European *pleh₁- (“to fill”)). The etymological sense is similar to being left speechless as a result of confusion: the nonplussed person can say or do “no more”.
Adjective sense 2 (“unaffected”) is probably from a misinterpretation of the first element of the word as the prefix non- meaning “not”.

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/word/nonplussed