swimmer UK /ˈswɪm.ə/US /ˈswɪm.ɚ/ noun5 •One who swims.The swimmer who is an expert does not exhibit his muscular force by violent movements, but exhibits some power which is invisible and which shows itself in perfect grace and reposefulness. — 1918 •[in the plural] (informal) A sperm. •A webfooted aquatic bird. •(UK, informal) A Norfolk dumpling. •A protuberance on the leg of a horse. formsswimmers