Definition
to wear formal attire for a particular event
穿正装；盛装
She dressed up for the wedding and looked absolutely stunning.
她为婚礼盛装打扮，看起来非常迷人。
They all dressed up in elegant attire for the formal dinner.
他们都穿上优雅的服装参加正式晚宴。
We need to dress up for the gala event.
我们需要为这个盛大的活动盛装打扮。
to don special attire to alter one's appearance
盛装打扮
Children often dress up in special costumes for Halloween.
孩子们经常在万圣节穿上特殊服装。
They will dress up in historical costumes for the party tonight.
他们今晚会穿上历史服装参加派对。
For the performance, he decided to dress up as his idol.
为了表演，他决定打扮成他的偶像。