A naturally occurring or synthetic compound consisting of large molecules made up of a linked series of repeated simple monomers WordNet 3.0 & Open English WordNet

A polymer is a substance or material consisting of very large molecules called macromolecules, composed of many repeating subunits. Wikipedia

Large molecule composed of many repeating subunits. Wikipedia Disambiguation

Substance made of giant molecules formed by the union of simple molecules OmegaWiki

A long or larger molecule consisting of a chain or network of many repeating units, formed by chemically bonding together many identical or similar small molecules called monomers. A polymer is formed by polymerization, the joining of many monomer molecules. Wiktionary

Molecule. Wiktionary (translation)