sweats
n. plural-only B1 Intermediate US //ˈswɛts// UK //swˈɛts// sweats
n. comfortable, loose clothes that you usually wear for exercising or relaxing at home. They are often made of soft, thick cotton.
n. loose-fitting trousers and a matching top made of heavy cotton jersey, typically worn for exercise or leisure. Often used as a collective term for a tracksuit or sweatpants.
I usually change into my sweats as soon as I get home.
After a long day at the office, she swapped her formal suit for a pair of comfortable sweats.
While once reserved strictly for the gym or the privacy of one's home, wearing stylish sweats in public has become a widely accepted fashion trend in many urban environments.
Usage
Pluralia tantum — takes a plural verb and is often used with 'pair of'.