subs. phr. (common).A concubine. For synonyms, see TART. Cf. Fr. mariage de la main gauche.
1663. KILLIGREW, The Parsons Wedding, i., 1 [DODSLEY, Old Plays (HAZLITT), 4th ed., 1875, xiv., p. 386]. Do you not know hes married according to the rogues liturgy? a LEFT-HANDED bridegroom.
1823. GROSE, A Classical Dictionary of the Vulgar Tongue, 3rd ed., s.v. LEFT-HANDED WIFE. A concubine: an allusion to an ancient German custom, according to which, when a man married his concubine, or a woman greatly his inferior, he gave her his left hand.