Do the British understand what "deism" is?

A couple of times, I’ve come across the word “deist” used by educated Britons as if it were simply the antonym of “atheist”, which is just incorrect usage and not a dialectal difference. I’m guessing most comparably educated Americans either know what “deist” means or don’t have the word “deist” in their vocabulary at all.

Maybe the idea of deism is more familiar to Americans because of its connection to the Founding Fathers and debates about the separation of church & state. Or maybe the examples of misuse that I came across were not representative.

Anyway, just curious.