Could somebody do the same for “nonplussed”? We have now given that poor poor word two opposite meanings. Currently, I have no idea what somebody means when they say they’re nonplussed.
Because with other classic examples, such as the verb "to table" meaning the opposite thing in the US and UK, you can at least always figure it out from context (if not from the accent, ha). And we know that "inflammable" is never used to mean fireproof.
But the two opposite meanings of "nonplussed", there's very often zero contextual indication as to which meaning is intended. And both meanings are used frequently, so it's in this total unresolved limbo state.
For me, it's the one word I won't use at all, precisely for this reason. There's simply no way to be properly understood.