A
dimer (, "two" + , "parts") is an
oligomer consisting of two structurally similar
monomers joined by bonds that can be either strong or weak,
covalent or
intermolecular. The term
homodimer is used when the two molecules are identical (e.g. A-A) and
heterodimer when they are not (e.g. A-B). The reverse of dimerisation is often called
dissociation.