ETYM Old Eng. fain, fagen, AS. faegen; akin to OS. fagan, Icel. faginn glad; AS. faegnian to rejoice, OS. faganôn, Icel. fagna, Goth. faginôn, cf. Goth. fahęds joy; and from the same root as Eng. fair. Srr Fair, Fawn to court favor.
(Archaic) Willing; happy.
(Homonym: feign).
Happy; inclined; pleased.

1. With pleasure; gladly
2. By preference
3. By desire