1. Not avoidable; incapable of being shunned or prevented; inevitable; necessary; as, unavoidable troubles.
2. Law Not voidable; incapable of being made null or void.
Unavoidable hemorrhage Med., hemorrhage produced by the afterbirth, or placenta, being situated over the mouth of the womb so as to require detachment before the child can be born.
-- Un*a*void*a*ble*ness, n. -- Un*a*void*a*bly, adv.