From Longman Dictionary of Contemporary Englishonce or twiceonce or twiceFEW/NOT MANYa few times I wrote to him once or twice, but he didn’t answer. → once
Examples from the Corpus
once or twice• He played for Northern Ireland once or twice.• He swallowed hard once or twice.• If needed, this can be repeated once or twice.• He was some one I would probably sleep with once or twice and then maybe become friends with afterward.• They merely mentioned it once or twice as a divine possibility.• Even he himself had had to beat it into the ground once or twice as one did a snake.• He'd been smashed on booze once or twice, but this was different.• And you have once or twice, haven't you?• Once or twice, he thought about calling his parents, but then decided not to. 