Entry 1 sense Webster, 1913 Acropolis /əkrŏʹpəlĭs/ · A·crop·o·lis · IPA /əˈkɹɒpəlɪs/ 01 n. The upper part, or the citadel, of a Grecian city; especially, the citadel of Athens. 1. The upper part, or the citadel, of a Grecian city; especially, the citadel of Athens.