up and down

Từ điển Oxford Advanced Learner 8th

ˌup and ˈdown idiom
1. moving upwards and downwards
• The boat bobbed up and down on the water.
2. in one direction and then in the opposite direction
• She was pacing up and down in front of her desk.
3. sometimes good and sometimes bad
• My relationship with him was up and down.
4. (NAmE, informal)if you swear up and down that sth is true, you say that it is definitely true
Main entry: ↑up_idiom