late 14c., "moral, virtuous," from well (adv.) + mannered. Meaning "with good manners" is from 1540s.
Entries linking to well-mannered
well adv.
"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.
mannered adj.
mid-15c., "having or possessed of manners or demeanor;" in compounds, "having manners of a certain kind;" from manner. Later, especially, "well-mannered." Also, especially in arts and literature, "characterized by mannerism, artificial, affected" (by 1801). The form ymanered is attested from late 14c. Compare mannerable "well-mannered" (late 15c.).