[teagoat]

huh - TIL: https://www.worldwidewords.org/qa/qa-com3.htm

TL;DR: Compleat and Complete were originally different spellings for the same word. In UK, compleat is still just an archaic spelling. In USA, compleat is used as an adjective to refer specifically to having all the necessary elements or skills.

[geoelectric]

I’ve never heard it in the USA outside of in old book titles. I’ll add The Compleat Enchanter by L. Sprague DeCamp as another prominent example. That’s from 1975 and probably a conscious reference to The Compleat Angler, along with a pun on a prior anthology called The Incomplete Enchanter.

Even the examples cited in the article seem like they’re out of older books deliberately invoking antiquity with the spelling. The only recent example (Bova, Mars, 1992) is from the SF/F genre where esoteric words like that get batted around more in general.

So I’m going to go with that being about as common in US English as UK—used for effect only.