noun / verb
wager
WAY-jer/ˈweɪdʒər/
A bet of money or something valuable on an uncertain outcome.
Two adults use chips to place wagers on a horse race.

Etymology
A wageure was a pledge or security. The connection to betting is the stake: something pledged and put at risk on an uncertain outcome.
In context
“But strong as he flies, he cannot out fly Margot. Bishop, I lay you ten gold pieces to one that the heron is mine.” “I cover your wager, sire,” said the Bishop.
More examples
- She makes a small wager on the championship game.
- We wager five dollars on who can finish first.
- He lost his wager when the favored horse finished last.
Forms
wager · wagers · wagered · wagering
bettor noun — A person who bets on uncertain outcomes.