Source : Webster's Revised Unabridged Dictionary (1913)

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 : WordNet®

unavoidably
     adv : by necessity; "the new council was inescapably of political
           meaning" [syn: {inescapably}, {ineluctably}, {inevitably}]