The Collaborative International Dictionary of English v.0.48:

Quitclaim \Quit"claim`\, v. t. [imp. & p. p. Quitclaimed
   (kw[i^]t"kl[=a]md`); p. pr. & vb. n. Quitclaiming.] (Law)
   To release or relinquish a claim to; to release a claim to by
   deed, without covenants of warranty against adverse and
   paramount titles.
   [1913 Webster]