sport shirt

or sports shirt


noun

a long- or short-sleeved soft shirt for informal wear by men, having a squared-off shirttail that may be left outside the trousers, usually worn without a tie.
Compare dress shirt.

Origin of sport shirt

First recorded in 1915–20

British Dictionary definitions for sports shirt

sports shirt

noun

a man's informal shirt, sometimes of knitted wool or cotton, which may be worn outside the trousers