gamble on someone or something
1. Lit. to make a wager on something concerning someone or something. I wouldn't gamble on it happening. Don't gamble on that horse. You'll be sorry.
2. Fig. to run a risk by choosing or depending on someone or something. I wouldn't gamble on Ted's being able to come. I don't think he can. Don't gamble on Ted. I'm almost sure he won't come.
1. To wager something on the outcome of some event: I gambled all my money on the first race. They don't like to gamble on poker games; they just play for fun.
2. To wager something on some participant in an event: I gambled $50 on my favorite horse.
3. To anticipate or foresee something: I didn't gamble on it raining, so I hadn't brought an umbrella.