macrocyclicEnglishOxford Dictionary of Englishmacrocyclic /ˌmakrə(ʊ)ˈsʌɪklɪk / ▸ adjective Chemistry relating to or denoting a ring composed of a relatively large number of atoms, such as occur in haem, chlorophyll, and several natural antibiotics. – DERIVATIVES macrocycle /ˈmakrə(ʊ)ˌsʌɪkl / noun