Old English weddung "state of being wed; pledge, betrothal; action of marrying," verbal noun from wed (v.). Meaning "nuptials, ceremony of marriage" is recorded from early 13c.; the usual Old English word for the ceremony was bridelope, literally "bridal run," in reference to conducting the bride to her new home. Wedding ring is from late 14c.; wedding cake is recorded from 1640s, as a style of architecture from 1879. Wedding dress is attested from 1779; wedding reception from 1856.
Old English weddian "to pledge oneself, covenant to do something, vow; betroth, marry," also "unite (two other people) in a marriage, conduct the marriage ceremony," from Proto-Germanic *wadja (source also of Old Norse veðja, Danish vedde "to bet, wager," Old Frisian weddia "to promise," Gothic ga-wadjon "to betroth"), from PIE root *wadh- (1) "to pledge, to redeem a pledge" (source also of Latin vas, genitive vadis "bail, security," Lithuanian vaduoti "to redeem a pledge"), which is of uncertain origin.
The sense has remained closer to "pledge" in other Germanic languages (such as German Wette "a bet, wager"); development to "marry" is unique to English. "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. Related: Wedded; wedding.
"marriage, wedding," 1550s, plural of nuptial. Now always plural, but Shakespeare uses the singular.