An Etymological Dictionary of the German Language/Annotated/wett
wett, adjective, ‘equal, even,’ from late Middle High German wętte, adjective, ‘paid off.’ A recent derivative of the noun Wette, feminine, ‘bet, wager,’ Middle High German wętte, węte, węt (tt), neuter and feminine, Old High German wętti, węti, neuter, ‘mortgage contract, legal obligation, pledge, stake (in a bet), compensation, fine’ (the last three meanings first occur in Middle High German). Compare Anglo-Saxon wędd, Old Icelandic veð, Gothic wadi, neuter, ‘pledge, earnest.’ From Old Teutonic wadjo-, the Romance cognates, Italian gaggio and French gage, ‘pledge,’ are borrowed. The following are also primitively allied to Teutonic Wette; Latin văs (vadis), ‘surety,’ vădimonium, ‘bail, security,’ Lithuanian vadůti, ‘to redeem a pledge,’ and perhaps also Greek ἄεθλος (root ϝεθ), ‘prize (of contest),’ which point to an Aryan root wedh.