marriage (n.) Look up marriage at Dictionary.com
c.1300, "act of marrying, entry into wedlock;" also "state or condition of being husband and wife;" from Old French mariage "marriage; dowry" (12c.), from Vulgar Latin *maritaticum (11c.), from Latin maritatus, past participle of maritatre "to wed, marry, give in marriage" (see marry (v.)). The Vulgar Latin word also is the source of Italian maritaggio, Spanish maridaje. Meaning "a union by marriage, a particular matrimonial union" is early 14c.; that of "wedding; the marriage ceremony; condition of being married" is from late 14c. Figurative use (non-theological) from early 15c.
[W]hen two people are under the influence of the most violent, most insane, most delusive, and most transient of passions, they are required to swear that they will remain in that excited, abnormal, and exhausting condition until death do them part. [G.B. Shaw, preface to "Getting Married," 1908]
Marriage counseling recorded by 1939. Marriage bed, figurative of marital intercourse generally, is attested from 1580s.