The word 'tracksuit' is a modern English compound, formed in the 20th century. The first element, 'track', refers to a prepared course for running or racing, thus evoking the context of athletics. The second element, 'suit', originates from the idea of clothes that 'follow' or match each other to form a set. Literally, a 'tracksuit' is a 'suit for the track'. Its meaning has broadened from specialized athletic wear worn for warming up or training on a running track to encompass a common category of casual, comfortable clothing.

Structure: track (a running course) + suit (a set of clothes) - track: From Middle English trak, from Old French trac, possibly of Germanic origin. In this compound, it functions as a modifier specifying the type of suit, relating to running or athletic activity. - suit: From Middle English sute, from Anglo-Norman French siwte, from a feminine past participle of a Romance verb meaning 'to follow'. In this compound, it functions as the head noun, denoting a set of garments.