Entry 1 sense Webster, 1913 Aquamarine /äkˌ-wəm-ẽr-ēn'/ · A·qua·ma·rine · IPA /ˌæk.wə.məˈɹiːn/ 01 n. A transparent, pale green variety of beryl, used as a gem. See Beryl. 1. A transparent, pale green variety of beryl, used as a gem. See Beryl.(Min.) See: Beryl