LSJ Gloss:ἑκώνwilling, of free will, readilyDodson:ἑκώνwilling, willinglywilling, willingly, voluntarily.
TBESG:ἑκώνvoluntarilyG:A ἑκών, -οῦσα, -όν [in LXX: Refs Exo.21:13, Job.36:19 * ;] willing, of one's own free will: Refs Rom.8:20, 1Co.9:17 (Cremer, 246).† (AS)
ἑκούσιον hekousion hek-oo'-see-on Neuter of a derivative from G1635; voluntarinessKJV Usage: willingly.