fan (advb.): Occurs twice in English Versions of the Bible, in the sense of "gladly": (1) in Job 27:22 as the rendering of barach, "to flee with haste" (from anything), "He would fain flee out of his hand," literally, as in in of the King James Version, "in fleeing he would flee"; (2) in Lu 15:16, as the translation of epithumeo, "to fix the mind or desire on," "He would fain have filled his belly with the husks which the swine did eat." the Revised Version (British and American) adds two instances: (1) Lu 13:31, "Herod would fain kill thee"; (2) Ac 26:28, "Thou wouldest fain make me a Christian.
⇒See the definition of fain in the KJV Dictionary
See ALMOST.