dress up

Từ điển Oxford Advanced Learner 8th

▪ I. ˌdress ˈup derived
to wear clothes that are more formal than those you usually wear
• There's no need to dress up— come as you are.
Main entry: ↑dress_derived
 
▪ II. ˌdress ˈup | ˌdress sb ˈup derived
to put on special clothes, especially to pretend to be sb/sth different
• Kids love dressing up.
• The boys were all dressed up as pirates.
• (BrE)dressing-up clothes
• (NAmE)dress-up clothes
Main entry: ↑dress_derived