The Collaborative International Dictionary of English v.0.48:

Marital \Mar"i*tal\ (m[a^]r"[i^]*tal), a. [F., fr. L. maritalis,
   fr. maritus belonging to marriage, n., a husband. See
   Marry, v.]
   1. Of or pertaining to a husband; as, marital rights, duties,
      authority. [archaic] "Marital affection." --Ayliffe.
      [1913 Webster]

   2. Of or pertaining to marriage; matrimonial.
      [PJC]

WordNet (r) 3.0 (2006):

marital
    adj 1: of or relating to the state of marriage; "marital
           status"; "marital fidelity"; "married bliss" [syn:
           marital, matrimonial, married]

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

MARITAL. That which belongs to marriage; as marital rights, marital duties.
     2. Contracts made by a feme sole with a view to deprive her intended
husband of his marital rights, with respect to her property, are a fraud
upon him, and may be set aside in equity. By the marriage, the husband
assumes the duty of paying her debts, contracted previous to the coverture,
and of supporting her during its existence; and he cannot, therefore, be
fraudulently deprived, by the intended wife, of those rights which enable
him to perform the duties which attach to him. 2 Cha. R. 42; Newl. Contr.
424; 1 Vern. 408; 2 Vern. 17; 2 P. Wms. 357, 674; 2 Bro. C. C. 345; 1 Ves.
jr. 22; 2 Cox, R. 28; 2 Beav. 528; 2 Ch. R. 81; White's. L. C. in Eq. *277;
1 Hill, Ch. R. 1, 4; 13 Maine, R. 124; 1 McMull. Eq. R. 237 3 Iredell's Eq.
R. 487; 4 Wash. C. C. R. 224.