Metamer
Pronunciation : Met"a*mer
Part of Speech : n.
Etymology : [See Metamere.] (Chem.)
Definition : Defn: Any one of several metameric forms of the same substance, or of different substances having the same composition; as, xylene has three metamers, viz., orthoxylene, metaxylene, and paraxylene.
Source : Webster's Unabridged Dictionary, 1913