macromoleculeEnglishOxford New American Dictionarymacromolecule /ˌmakrōˈmäləkyo͞ol, ˌmækroʊˈmɑləkjul / ▸ noun Chemistry a molecule containing a very large number of atoms, such as a protein, nucleic acid, or synthetic polymer. – DERIVATIVES macromolecular /-məˈlekyələr/ adjective