"act of transferring title of ownership," 1650s, from Latin abalienationem (nominative abalienatio), in law, "transfer of property, sale," noun of action from past-participle stem of abalienare "to separate, transfer the ownership of," from ab "off, away from" (see ab-) + alienare "to separate" (from alius "another, other, different," from PIE root *al- (1) "beyond").