> Bewildered; unsure how to respond or act. [from 17th c.]
> (proscribed, US, informal) Unfazed, unaffected, or unimpressed. [from 20th c.]
Huh. And then https://en.wiktionary.org/wiki/Appendix:Glossary#proscribed is fun. But then, both “nonplussed” and “proscribed” are weird words where if you used them in a sentence and asked someone unfamiliar with them to guess their meaning they’d tend to guess quite the wrong direction. Something like this: “I guess ‘nonplussed’ means ‘not plussed’ like… not… benefited by? And ‘proscribed’, ‘pro-’ means in favour of and ‘scribed’ means written, so I suppose it means this is the way you should write it.”