noun Chemistry.

a molecule composed of two identical, simpler molecules.
a polymer derived from two identical monomers.

Compare oligomer.

Origin of dimer

First recorded in 1905–10; di-1 + -mer
Related formsdi·mer·ic [dahy-mer-ik] /daɪˈmɛr ɪk/, adjective
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

British Dictionary definitions for dimer



  1. a molecule composed of two identical simpler molecules (monomers)
  2. a compound consisting of dimers

Word Origin for dimer

C20: from di- 1 + -mer
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

dimer in Medicine




A molecule consisting of two identical simpler molecules.
A chemical compound consisting of such molecules.
Related formsdi•meric (dī-mĕrĭk) adj.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

dimer in Science



Any of various chemical compounds made of two smaller identical or similar molecules (called monomers) that are linked together. Dimers are linked by hydrogen bonds, coordinate bonds, or covalent bonds. Sucrose is a dimer composed of the monomers glucose and fructose.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.