gage n.

"ascertain by exact measurements," mid-15c., from Anglo-French gauge (mid-14c.), from Old North French gauger "standardize, calibrate, measure" (Old French jaugier), from gauge "gauging rod," a word of unknown origin. Perhaps from Frankish *galgo "rod, pole for measuring" or another Germanic source (compare Old Norse gelgja "pole, perch," Old High German galgo; see gallows). Related: Gauged; gauging. The figurative use is from 1580s. "The spelling variants gauge and gage have existed since the first recorded uses in Middle English, though in American English gage is found exclusively in technical uses" [Barnhart].

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.