Term: irregular macromolecule https://doi.org/10.1351/goldbook.I03256 Definition: A macromolecule the structure of which essentially comprises the repetition of more than one type of constitutional unit or a macromolecule the structure of which comprises constitutional units not all connected identically with respect to directional sense. Related Terms: 1) macromolecule (http://doi.org/10.1351/goldbook.M03667). 2) constitutional unit (http://doi.org/10.1351/goldbook.C01288). Source: PAC, 1996, 68, 2287. 'Glossary of basic terms in polymer science (IUPAC Recommendations 1996)' on page 2289 (https://doi.org/10.1351/pac199668122287) Citation: 'irregular macromolecule' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. https://doi.org/10.1351/goldbook.I03256 License: The IUPAC Gold Book is licensed under Creative Commons Attribution-ShareAlike CC BY-SA 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) for individual terms. Disclaimer: The International Union of Pure and Applied Chemistry (IUPAC) is continuously reviewing and, where needed, updating terms in the Compendium of Chemical Terminology (the IUPAC Gold Book). Users of these terms are encouraged to include the version of a term with its use and to check regularly for updates to term definitions that you are using.