Английский Этимологический словарь - well (adv.)

- "in a satisfactory manner," O.E. wel, from the same Gmc. source as O.E. willan "to wish" (see will (2)), from PIE *wel-, *wol-. Also used as an interjection and an expression of surprise in O.E. Well-done "thoroughly cooked" is attested from 1747; well-nigh is O.E. wel neah. Wellaway is M.E. alteration of O.E. wa la wa, from wa "woe." Well-done (of meat) is first attested 1846; well-known is from 1470; well-hung in male genital sense is from 1611; well off in the sense of "comfortable" is from 1733; well-to-do in this meaning is from 1825; well-heeled is from 1897 (see heel (n.)).