G1635
ἑκών
voluntarily
ἑκών, -οῦσα, -όν [in LXX: Exo.21:13, Job.36:19 * ;] willing, of one's own free will: Rom.8:20, 1Co.9:17 (Cremer, 246).† (AS)
The KJV translates G1635 in the following manner:
willingly (4x)
Full Thayer's lexicon entry
ἑκών — hekṓn
ἑκών, ἑκοῦσα, ἑκον, unforced, voluntary, willing, of one's own will, of one's own accord: Rom 8:20; 1Co 9:17. (From Homer down.)
2 occurrences
Romans (1), I Corinthians (1)