macromoleculeEnglishOxford Dictionary of Englishmacromolecule /ˌmakrəʊˈmɒlɪkjuːl / ▸ noun Chemistry a molecule containing a very large number of atoms, such as a protein, nucleic acid, or synthetic polymer. – DERIVATIVES macromolecular /ˌmakrəʊməˈlɛkjʊlə / adjective