Meaning: If you wait up, you stay up late at night waiting for something or someone.Synonym: stay up, sit up (British)
- wait up I'll be home late tonight, but don't wait up. You need your sleep.
- wait up for sb/sth Did your mother wait up for you when you were a teenager staying out late at parties and clubs?
During the FIFA World Cup my son watched all the matches live on TV, and to see them he had to wait up