Wed
Old English weddian, from the Germanic base of Scots wed ‘a pledge’; related to Latin vas ‘surety’, also to gage1.
wiktionary
From Middle English wedden, weddien, from Old English weddian(“to pledge; wed”), from Proto-West Germanic *waddjōn, from Proto-Germanic *wadjōną(“to pledge”), from *wadją(“pledge”), ultimately from Proto-Indo-European *wedʰ-(“to pledge”).
Cognate with Scots wed, wod, wad(“to wed”), Saterland Frisian wädje(“to bet, wager”), West Frisian wedzje(“to bet, wager”), Low German and Dutch wedden(“to bet”), German wetten(“to bet”), Danish vædde(“to bet”), Swedish vädja(“to appeal”), Icelandic veðja(“to bet”); more distantly, to Sanskrit वधू(vadhū́, “bride”). Related also to gage, engage, and wage.
etymonline
wed (v.)
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.
