Matrimony, n.
Etymology: [OE. matrimoine, through Old French, fr. L. matrimonium, fr. mater mother. See Mother.]
1. The union of man and woman as husband and wife; the nuptial state; marriage; wedlock. If either of you know any impediment, why ye may not be lawfully joined together in matrimony, ye do now confessit. Book of Com. Prayer (Eng. Ed. )
2. A kind of game at cards played by several persons. Matrimony vine (Bot.), a climbing thorny vine (Lycium barbarum) of the Potato family. Gray.
Syn. -- Marriage; wedlock. See Marriage.
Shades of meaning
Fernald has no entry of its own for matrimony; he lists it under marriage.
Where he writes about it:
Matrimony denotes the state of those who are united in the relation of husband and wife; marriage denotes primarily the act of so uniting, but is extensively used for the state as well. — from marriage
Wedlock, a word of specific legal use, is the Saxon term for the state or relation denoted by matrimony. — from marriage