LSJ Gloss:αἱρετικόςable to chooseDodson:αἱρετικόςfactiousdisposed to form sects, sectarian, heretical, factious.
Strong's:αἱρετικός a schismaticDerivation: from the same as G140;KJV Usage: heretic (the Greek word itself). G140
TBESG:αἱρετικόςschismaticG:A αἱρετικός, -ή, όν (< αἱρέομαι), __1. capable of choosing (Plat.). __2. causing division, heretical, factious (Cremer, 614): as subst., Tit.3:10. † (AS)
Thayer:1) fitted or able to take or choose a thing 2) schismatic, factious, a follower of a false doctrine 3) heretic
αἱρετικός aihretikos hahee-ret-ee-kos' From the same as G140; a schismatic . (“heretic” is the Greek word itself.)KJV Usage: heretic [the Greek word itself].
αὐθαίρετος authairetos ow-thah'ee-ret-os From G846 and the same as G140; self chosen, that is, (by implication) voluntaryKJV Usage: of own accord, willing of self.