1. An agreement usually between two parties that the one who has made an incorrect prediction about an uncertain outcome will forfeit something stipulated to the other; a wager.
2. An amount or object risked in a wager; a stake.
3. One on which a stake is or can be placed:
Our team is a sure bet to win.
4. A plan or an option considered with regard to its probable consequence:
Your best bet is to make reservations ahead of time.
5. Informal A view; an opinion:
My bet is that the rain will hold off.
6. To stake (an amount, for example) in a bet.
7. To make a bet with:
I bet them that we would be first.
8. To make a bet on (a contestant or an outcome).
9. To maintain confidently, as if making a bet:
I bet they were surprised by the news.
10. To make or place a bet.
11. Of course; surely.
12. [Origin unknown]
13. The central meaning shared by these nouns is “something valuable risked on an uncertain outcome”:
placed a 50-dollar bet on a horse in the first race;
raising the ante in a poker game;
won the whole pot in bridge;
defeated her opponent and took the stakes;
laid a wager on who would get the role.