Answer:
a molecule, containing a very large number of atoms, such as, protein, nucleic acid, or synthetic polyme.
Explanation:
A macromolecule is a very large molecule, such as protein, mostly commonly composed of the polymerization of smaller subunits, called monomers. They are typically composed of thousands of atoms, or more. A substance that is composed of monomers is called a polymer.
Easier version to understand: Macromolecules are large, complex molecules.
I hope this helps you ^^