Bouvier's Law Dictionary, Revised 6th Ed (1856):

PARENTS. The lawful father and mother of the party spoken of. 1 Murph. R.
336; 11 S. & R. 93.
     2. The term parent differs from that of ancestor, the latter embracing
not only the father and mother, but every per ascending line. It differs
also from predecessor, which is applied to corporators. Wood's Inst. 68; 7
Ves. 522; 1 Murph. 336; 6 Binn. 255. See Father; Mother.
     3. By the civil law grandfathers and grandmothers, and other
ascendants, were, in certain cases, considered parents. Dict. de Jurisp.
Parente. Vide 1 Ashm. R. 55; 2 Kent, Com. 159; 5 East, R. 223; Bouv. Inst.
Index, h.t.