If you say that someone is round the twist, you mean that their ideas or behaviour are very strange or foolish. You would have to be really round the twist to get pleasure out of this. This man's round the twist. Note: You can say that someone goes round the twist if they start to behave in a crazy way, often because they are bored or annoyed by something. Most of them go round the twist in the end, you know. His predecessor killed himself. I'd go round the twist if I didn't work. Compare with round the bend.