from German Isomorphismus, 1828, coined by German chemist Eilhard Mitscherlich (1794-1863) from isomorph; see isomorphic. Related: Isomorph.
isomorphism i·so·mor·phism (ī'sə-môr'fĭz'əm)
n.
A similarity in form, as in organisms of different ancestry.
A close similarity in the crystalline structure of two or more substances of similar chemical composition.