ɔːˈθɒɹɪˌteɪtɪv əˈθɔɹɪˌteɪtɪv ˈɔθəɹaɪzd ˈɔːθəɹaɪzd dɪˈfɪn.ɪt.ɪv ɪmˈpɔːtənt ɪmˈpɔɹtənt endowed with authority an authoritative communique the authorized biography having authority or ascendancy or influence an important official the captain's authoritative manner of recognized authority or excellence the definitive work on Greece