early 15c., manumitten, "set (a slave or captive) free," from Latin manumittere "to release from one's power, set at liberty, emancipate," literally "to send from one's 'hand'" (i.e. "control"), from the phrase manu mittere "release from control," from manu, ablative of manus "power of a master," literally "hand" (from PIE root *man- (2) "hand") + mittere "let go, release" (see mission). Related: Manumitted; manumitting. Alternative form manumiss, manumise was sometimes used 16c.-19c.