You might have one on the side (3)

I believe the answer is:

bet

(Other definitions for bet that I've seen before include "Wager, or the sum waged" , "Money risked on a gamble" , "'Stake, wager (3)'" , "Speculation" , "Wager, speculate" .)

I've seen this clue in The New York Times.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.