"NOTE: The use of nonplussed to mean 'unimpressed' is an Americanism that has become increasingly common in recent decades and now appears frequently in publish

"NOTE: The use of nonplussed to mean 'unimpressed' is an Americanism that has become increasingly common in recent decades and now appears frequently in published writing. It apparently arose from confusion over the meaning of nonplussed in ambiguous contexts, and it continues to be widely regarded as an error." Read: only dumb people use it this way.