leisure suit n (1975) : a suit consisting of a shirt jacket and matching trousers for informal wear – Websters Dictionary

Leisure suits first originated in Europe in the 1700’s but the 1970’s saw the emergence of the polyester version, sported by lounge lizards across the United States.

While acting as an informal alternative to sports coats or suits, the leisure suit eventually because a cause ridicule, with certain restaurants and businesses going so far to ban them from being worn in their establishments.