if you do something on the off-chance, you do it because you hope you will get or find something or someone, even if it is not very likely I don't think he works in the shop on Saturdays, but you could stop by on the off-chance. (often + that ) Journalists often investigate film stars' private lives on the off-chance that they might find something scandalous. (often + of + doing sth) She flew in from New York on the off-chance of getting tickets to see Becker play his last match at Wimbledon.