Unavoidable \Un`a*void"a*ble\, a.

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. --Blackstone.

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.

Source: Webster's Revised Unabridged Dictionary (1913)