From Longman Dictionary of Contemporary Englishsweatpantssweat‧pants /ˈswetpænts/ noun [plural] American English DCCDSloose warm trousers, worn especially for sport or relaxation
Examples from the Corpus
sweatpants• It saddened me to see him in dark sweatpants again.• I put on my fuchsia sweatpants.• In the pocket of her dark green sweatpants is a list of the starters.• She is one of the few women alive who can look elegant in sweatpants and a warm-up jacket.• When she speaks the code of basketball, she could be any guy in sweatpants and smelly sneakers.• No, he had no recollection of looking at the sweatpants the state put into evidence. 