polymer

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun Any of numerous natural and synthetic compounds of usually high molecular weight consisting of up to millions of repeated linked units, each a relatively light and simple molecule.

from The Century Dictionary.

• noun In chem., a compound which is polymeric with some other compound; a polymeride.

from the GNU version of the Collaborative International Dictionary of English.

• noun (Chem.), Formerly also written polymere. Any one of two or more substances related to each other by polymerism; specifically, a substance produced from another substance by chemical polymerization.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun organic chemistry 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.
• noun A material consisting of such polymer molecules.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a naturally occurring or synthetic compound consisting of large molecules made up of a linked series of repeated simple monomers