'athletic-looking' is a compound of 'athletic' + 'looking'. 'athletic' originates from Greek, specifically the word 'athletikos' (from 'athletes'/'athlos'), and 'looking' comes from Old English 'lōcian' meaning 'to look'.

'athletic' entered English via Latin/French forms (e.g. Middle French 'athlétique') and Middle English adaptations, while 'look' evolved from Old English 'lōcian' to the modern verb 'look'; the compound form 'athletic-looking' is a modern English formation combining adjective + present-participial adjective.

Initially, 'athletic' meant 'pertaining to athletes or athletic contests'; over time it broadened to describe physical fitness and physique. 'Looking' originally meant 'to direct one's gaze' but developed a use forming adjectives that describe appearance (e.g. 'good-looking'); together they now mean 'appearing physically fit'.