a. 1. Not avoidable; incapable of being shunned or prevented; inevitable; necessary; as, unavoidable troubles. [ 1913 Webster ]

2. (Law) Not voidable; incapable of being made null or void. Blackstone. [ 1913 Webster ]

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. [ 1913 Webster ]

-- Un`a*void"a*ble*ness, n. -- Un`a*void"a*bly, adv. [ 1913 Webster ]