Entry 1 sense Webster, 1913 Carbonate /kärʹbənāt/ · Car·bon·ate · IPA /ˈkɑɹbəneɪt/ 01 n. A salt or carbonic acid, as in limestone, some forms of lead ore, etc. 1. A salt or carbonic acid, as in limestone, some forms of lead ore, etc.(Chem.)