a. [ L. invincibilis: cf. F. invincible. See In- not, and Vincible. ] Incapable of being conquered, overcome, or subdued; unconquerable; insuperable; as, an invincible army, or obstacle. [ 1913 Webster ]
Lead forth to battle these my sons Invincible. Milton.
-- In*vin"ci*ble*ness, n. -- In*vin"ci*bly, adv. [ 1913 Webster ]