The word nonplussed has a different meaning than many people think. Nonplussed seems to be taking on an entirely new meaning simply because it is misused so often, by so many writers.
Often, you can see writers (or hear speakers) use “nonplussed” to describe a feeling that’s related to the idea “I don’t care” or “she doesn’t care”.
I learned about this while watching old episodes of 30 Rock on Netflix! Tracey Jordan said something like “I am truly nonplussed and that is in the proper meaning of the word nonplussed”, which made me think “hmmm”, so I looked it up. Who’d expected to learn about language from Tracey Jordan? (Well, okay, really from 30 Rock writer Tina Fey.)
The real definition of nonplussed
Nonplussed means “so surprised I don’t know how to respond”.
The Oxford Dictionary’s usage note for the definition of nonplussed says:
In standard use nonplussed means ‘surprised and confused’…
Merriam-Webster sheds a bit more light on it with this definition:
nonplussed transitive verb
: to cause to be at a loss as to what to say, think, or do : perplex
However, people often use nonplussed to mean “indifferent” or “unconcerned” or sometimes even “disinterested”.
North American informal Not disconcerted; unperturbed.
Dictionaries may attribute this “wrong” usage to North Americans but I hear it used that way everywhere, including Australia.
Isn’t it interesting how the meaning of a word might change completely over time—and even change to a meaning that’s almost opposite to the real definition?
By the way, “nonplussed” does not need a hyphen. It is “nonplussed”, not “non-plussed”.