wager

Etymology 1

From Middle English wajour, wageour, wager, from Old Northern French wageure, from wagier (“to pledge”) (compare Old French guagier, whence modern French gager). See also wage.

noun

1. Something deposited, laid, or hazarded on the event of a contest or an unsettled question; a bet; a stake; a pledge.
   1842-43, Edgar Allan Poe, "The Mystery of Marie Roget" “This thicket was a singular, an exceedingly singular one. It was unusually dense. Within its naturally walled enclosure were three extraordinary stones, forming a seat with a back and footstool.… , whose boys were in the habit of closely examining the shrubberies about them in search of the bark of the sassafras. Would it be a rash wager – a wager of one thousand to one – that a day never passed over the heads of these boys without finding at least one of them ensconced in the umbrageous hall, and enthroned upon its natural throne? Those who would hesitate at such a wager, have either never been boys themselves, or have forgotten the boyish nature."
2. That on which bets are laid; the subject of a bet.
3. (law) A contract by which two parties or more agree that a certain sum of money, or other thing, shall be paid or delivered to one of them, on the happening or not happening of an uncertain event.
   Besides these Plates, the Wagers may be as the Persons please among themselves, but the Horses must be evidenced by good Testimonies to have been bred in Ireland. 1673, Sir William Temple, Advancement of Trade in Ireland
4. (law) An offer to make oath.

verb

1. (transitive) To bet something; to put it up as collateral.
   I'd wager my boots on it.
2. (intransitive, figurative) To suppose; to dare say.
   I'll wager that Johnson knows something about all this.

Etymology 2

From the verb, wage + -er.

noun

1. Agent noun of wage; one who wages.
   They were wagers of warfare against the wilderness and the Indians, and founders of families and towns. 1912, Pocumtack Valley Memorial Association, History and Proceedings of the Pocumtuck Valley Memorial Association, page 65
   Hatshepsut was no wager of wars, no bloodstained conqueror. 1957, Elsa Maxwell, How to Do It; Or, The Lively Art of Entertaining, page 7