The term "man's formal dress" can encompass a variety of attire options that can make it difficult to find the perfect synonym. Some popular alternatives include "tuxedo," which is a formal suit traditionally worn for black-tie events. A "suit and tie" is also a formal option, typically consisting of a matching jacket and pants, a dress shirt, and a tie. A "dinner jacket" is a variation of the tuxedo with a shorter length and no tails. A three-piece suit is another option that includes a vest to complete the formal look. Ultimately, the synonym chosen will depend on the formality of the event and personal style preferences.