>>33301502 (OP)>has elements of formalwareWat? Gowns don't have a monopoly on skirts, and not all sundresses hug the body.
Sundresses are casualware with thin and breathing fabric, making them ideal in the sun. They signify lightheartedness and youthfulness because of the playful motion of the thin, uncontrollable fabric in the wind.
To find the male counterpart, you need to identify the uniquely female feature, because a sundress on a male would look equally playful too.
When a woman wears a sundress, it signals youth, free spirit and innocence. What on a male signals youth, free spirit and innocence? I'm trying to think but I can't come up with something. Shirtless, with naively thick shorts, signaling an eagerness to take on the world, idk