Entries linking to well-acquainted
"in a satisfactory manner," Old English wel "abundantly, very, very much; indeed, to be sure; with good reason; nearly, for the most part," from Proto-Germanic *wel- (source also of Old Saxon wela, Old Norse vel, Old Frisian wel, Dutch wel, Old High German wela, German wohl, Gothic waila "well"), from PIE root *wel- (2) "to wish, will" (source also of Sanskrit prati varam "at will," Old Church Slavonic vole "well," Welsh gwell "better," Latin velle "to wish, will," Old English willan "to wish;" see will (v.)).
Also used in Old English as an interjection and an expression of surprise. The adjective was in Old English in the sense "in good fortune, happy," from the adverb; sense of "satisfactory" is from late 14c.; "agreeable to wish or desire" is from mid-15c.; "in good health, not ailing" is from 1550s. Well-to-do "prosperous" is recorded by 1794.
early 13c., "personally known;" past-participle adjective from acquaint (v.). Of skills, situations, etc., from late 15c.
I have been one acquainted with the night.
I have walked out in rain — and back in rain.
I have outwalked the furthest city light.
[Robert Frost, from "Acquainted with the Night"]
Acquaint also was used as an adjective (late 13c.) "acquainted."