Abbott-Smith Manual Greek Lexicon
ἀκυρόω (G208)
3 **† ἀκυρόω , -ῶ ( κῦρος , authority ), [in LXX: I Es 6:32 , IV Mac 6 *;] to revoke , invalidate (MM, VGT , s.v.): Mt 15:6 , Mk 7:13 , Ga 3:17 (Plut.).†
G. Abbott-Smith, A Manual Greek Lexicon of the New Testament (1922) — public domain