Origin and history of wed

Middle English wedden, "take a husband or wife, get married," from Old English weddian "to pledge oneself, covenant to do something, vow; betroth, marry," also, of a priest, etc., "unite (a man and woman) in a marriage, conduct the marriage ceremony," from Proto-Germanic *wadanan (source also of Old Norse veðja, Danish vedde "to bet, wager," Old Frisian weddia "to promise," Gothic ga-wadjon "to betroth").

According to Watkins this is from PIE *wadh- (1) "to pledge, to redeem a pledge" (source also of Latin vas, genitive vadis "bail, security," Lithuanian vaduoti "to redeem a pledge"). Boutkan acknowledges the cognates but suspects substrate origin.

The sense has remained closer to "pledge" in other Germanic languages (such as German Wette "a bet, wager"); its specialization to "marry" is unique to English. In Middle English it still also could mean "to wager."

Oldest use is of a man, "take (a woman) as wife;" in reference to a woman, directly, from late 14c.; previously in passive constructions, be wedded, was wedded. "Originally 'make a woman one's wife by giving a pledge or earnest money', then used of either party" [Buck].

Passively, of two people, "to be joined as husband and wife," from c. 1200. Figuratively, "join closely in affection," by 1818. Related: Wedded; wedding.