unmarried (adj.)

prefix of negation, Old English un-, from Proto-Germanic *un- (source also of Old Saxon, Old Frisian, Old High German, German un-, Gothic un-, Dutch on-), from PIE *n- (source of Sanskrit a-, an- "not," Greek a-, an-, Old Irish an-, Latin in-), combining form of PIE root *ne- "not." Often euphemistic (such as untruth for "lie").

The most prolific of English prefixes, freely and widely used in Old English, where it forms more than 1,000 compounds. It underwent a mass extinction in early Middle English, but emerged with renewed vigor 16c. to form compounds with native and imported words. It disputes with Latin-derived cognate in- (1) the right to form the negation of certain words (indigestable/undigestable, etc.), and though both might be deployed in cooperation to indicate shades of meaning (unfamous/infamous), typically they are not.

It also makes words from phrases (such as uncalled-for, c. 1600; undreamed-of, 1630s; uncome-at-able, 1690s; unputdownable, 1947, of a book; un-in-one-breath-utterable, Ben Jonson; etc., but the habit is not restricted to un-; such as put-up-able-with, 1812). As a prefix in telegramese to replace not and save the cost of a word, it is attested by 1936.

c. 1300, marien, of parents or superiors, "to give (offspring) in marriage," also intransitive, "to enter into the conjugal state, take a husband or wife," from Old French marier "to get married; to marry off, give in marriage; to bring together in marriage," from Latin marītāre "to wed, marry, give in marriage" (source of Italian maritare, Spanish and Portuguese maridar), from marītus (n.) "married man, husband," which is of uncertain origin.

Perhaps ultimately "provided with a *mari," a young woman, from PIE *mari-, *mori- "young wife, young woman" (source also of Welsh morwyn "girl, maiden," Middle Welsh merch "daughter"), akin to *meryo- "young man" (source of Sanskrit marya- "young man, suitor").

By early 14c. as "to take (someone) in marriage, take for a husband or wife;" by late 14c. as "become husband and wife according to law or custom; get married (to one another)." Transitive sense, of a priest, etc., who performs the rite of marriage, "to unite in wedlock or matrimony," by 1520s.

Figurative meaning "unite intimately or by some close bond of connection" is from early 15c. Related: Married; marrying. Phrase the marrying kind, describing one inclined toward marriage and almost always used with a negative, is attested by 1824, probably short for marrying kind of men, which is from a popular 1756 essay by Chesterfield.

In some Indo-European languages there were distinct "marry" verbs for men and women, though some of these have become generalized. Compare Latin ducere uxorem (of men), literally "to lead a wife;" nubere (of women), perhaps originally "to veil" [Buck]. Also compare Old Norse kvangask (of men) from kvan "wife" (see quean), so, "take a wife;" giptask (of women), from gipta, a specialized use of "to give" (see gift (n.)), so, "to be given."