early 13c. (intransitive), "waver, vacillate, lack steadfastness," probably from a Scandinavian source (compare Old Norse vagga "a cradle," Danish vugge "rock a cradle," Old Swedish wagga "fluctuate, rock" a cradle), and in part from Old English wagian "move backwards and forwards;" all from Proto-Germanic *wag- (source also of Old High German weggen, Gothic wagjan "to wag"), probably from PIE root *wegh- "to go, move, transport in a vehicle."
Transitive meaning "move (something) back and forth or up and down" is from c. 1300; of dogs and their tails from mid-15c.: "and whanne they [hounds] see the hure maystre they wol make him cheere and wagge hur tayles upon him." [Edward, Duke of York, "The Master of Game," 1456]. Related: Wagged; wagging. Wag-at-the-wall (1825) was an old name for a hanging clock with pendulum and weights exposed.
c. 1300, "a payment for services rendered, reward, just deserts;" mid-14c., "salary paid to a provider of service," from Anglo-French and Old North French wage (Old French gage) "pledge, pay, reward," from Frankish *wadja- or another Germanic source (compare Old English wedd "pledge, agreement, covenant," Gothic wadi "pledge"), from Proto-Germanic *wadi- (see wed (v.)).
Also from mid-14c., "a pledge, guarantee, surety" (usually in plural), and (c. 1400) "a promise or pledge to meet in battle." The "payment for service" sense by late 14c. extended to allotments of money paid at regular intervals for continuous or repeated service. Traditionally in English wages were payment for manual or mechanical labor and somewhat distinguished from salary or fee. Modern French cognate gages (plural) means "wages of a domestic," one of a range of French "pay" words distinguished by class, such as traitement (university professor), paye, salaire (workman), solde (soldier), récompense, prix. The Old English word was lean, related to loan and representing the usual Germanic word (Gothic laun, Dutch loon, German Lohn). Wage-earner attested from 1871.
c. 1300, "give (something) as surety, deposit as a pledge," from Old North French wagier "to pledge" (Old French gagier, "to pledge, guarantee, promise; bet, wager, pay," Modern French gager), from wage (see wage (n.)). Meaning "to carry on, engage in" (of war, etc.) is attested from mid-15c., probably from earlier sense of "to offer as a gage of battle, agree to engage in combat" (mid-14c.). Related: Waged; waging.
c. 1600 (intransitive); 1610s (transitive), from wager (n.). Related: Wagered; wagering.
c. 1300, wajour "a promise, a vow, something pledged or sworn to;" also "a bet, a wager; stakes, something laid down as a bet," from Anglo-French wageure, Old North French wagiere (Old French gagiere, Modern French gageure) "pledge, security," from wagier "to pledge" (see wage (n.)).
late 15c. (implied in waggling), frequentative of wag (v.). Compare Dutch waggelen "to waggle," Old High German wagon "to move, shake," German wackeln "to totter." Transitive sense from 1590s. Related: Waggled.
"four-wheeled vehicle to carry heavy loads," late 15c., from Middle Dutch wagen, waghen, from Proto-Germanic *wagna- (source also of Old English wægn, Modern English wain, Old Saxon and Old High German wagan, Old Norse vagn, Old Frisian wein, German Wagen), from PIE *wogh-no-, suffixed form of root *wegh- "to go, move, transport in a vehicle" (source also of Latin vehiculum). It is thus related to way.
In Dutch and German, it is the general word for "a wheel vehicle;" its use in English is a result of contact through Flemish immigration, Dutch trade, or the Continental wars. It has largely displaced the native cognate, wain. Spelling preference varied randomly between -g- and -gg- from mid-18c., until American English settled on the etymological wagon, while waggon remained common in Great Britain. Wagon-train is attested from 1810. Phrase on the wagon "abstaining from alcohol" is attested by 1904, originally on the water cart.
