Find the word definition

Wiktionary
sports bra

n. A type of bra that is more supportive than an everyday bra, worn when practise sports or other physical activities.

Wikipedia
Sports bra

A sports bra is a bra that provides additional support to female breasts during physical exercise. Sturdier than typical bras, they minimize breast movement, alleviate discomfort, and reduce potential damage to chest ligaments. Many women wear sports bras to reduce pain, and physical discomfort caused by breast movement during exercise. Some sports bras are designed to be worn as outerwear during exercise such as jogging. Larger breasted women may be prevented from taking part in sports or exercise when their breasts move excessively.