From Longman Dictionary of Contemporary Englishsports jacketˈsports ˌjacket noun [countable] DCCa man’s jacket that is not part of a suit
Examples from the Corpus
sports jacket• They were both in their fifties - she in a tweed coat, he in a sports Jacket and flannels.• Jacket taken: A sports jacket worth £100 was stolen from a car at Cod Beck reservoir near Osmotherley.• He was wearing blue-gray corduroy trousers, a sports jacket, no tie, lace-up shoes that had cost some money.• He wore a brown sports jacket with a black roll neck sweater.• Harris tweed sports jacket, cavalry twill slacks. 