Douglas Harper's Etymology Dictionary
1728, "having good acquaintance with," from well (adv.) + acquainted.
Usage examples of "well-acquainted".
He was well-acquainted with Ricketts and had spoken to him before placing the Fire Zouaves behind him.
I am not well-acquainted with Misses Stockard, but it is not difficult to see why an intelligent person would object to an alliance with Newbold.
You are always diverting, and if your sportiveness leads you now and then to say some odd things I fancy I am too well-acquainted with you to believe you mean them.
Inchkeith schooled them on what to look for and how to go about it, so that at the end of several hours search they were well-acquainted with the methods of miners.
Joat had become well-acquainted with the station's drills but, with survival skills as finely honed as hers were, she had put the suit on when the klaxon sounded Red Alert.
Wratha and her chiefest lieutenants would come down on foot out of Wrathspire, and the dog-Lord and his whelps were well-acquainted with the way up from Mangemanse (though in fact Nestor knew they would come by flyer, and late, of course, in order that Canker could make his entry in accustomed style).
Hap, as a professional brawn, you are surely well-acquainted with the peculiarities of these persons.
However, he was flattered to discover how well-acquainted they were with Discovery's log, it had become one of the classic records of the Space Age.