noun. A molecule that can combine with other molecules to form a polymer.

noun. The basic conceptual building unit of a polymer; a molecule of low molecular weight which may combine with other molecules to form a molecule in a chain or branched form having high molecular weight.

noun. A relatively small molecule which can be covalently bonded to other monomers to form a polymer.

noun. a simple compound whose molecules can join together to form polymers

""A fliD-deficient mutant becomes non-motile because it lacks flagellar filaments and leaks flagellin monomer out into the medium.""