dēˈau̇ˌläs, dēˈȯˌl- noun
( plural diau·li -au̇ˌlē, -ȯˌlī)
Etymology: Greek, from di- + aulos pipe, reed instrument like an oboe, racecourse — more at alveolus
: the double course for footraces in ancient Greece in which the contestants ran down one side of the stadium, turned round a goal, and returned to the starting point