or sports shirt
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.
Why Do We Call It A “Wife Beater” Shirt?How did the violent term "wife beater" become associated with a piece of clothing anyway? For that, we take an etymological and sartorial tour through time.
Compare dress shirt.
Origin of sport shirt
First recorded in 1915–20
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
British Dictionary definitions for sports shirt
a man's informal shirt, sometimes of knitted wool or cotton, which may be worn outside the trousers
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012