Questions about example sentences with, and the definition and usage of "Overdress"

A: to dress in a formal fashion for a informal area, a example is wearing a suit to a picnic or a low cost restaurant

A: Generally speaking, the term, 'overdressed' refers to dressing up, such as wearing a suit and tie. I think you mean by overdressed is that the person should not wear too much clothing. If that's the case, try using a different phrase. "Dress too warmly" might work!