FAIN Meaning of FAIN in English adj. & adv. archaic --predic.adj. (foll. by to + infin.) 1 willing under the circumstances to. 2 left with no alternative but to. --adv. gladly (esp. would fain). Etymology: OE f{aelig}gen f. Gmc Oxford English vocab. Оксфордский английский словарь. 2012