n. [ See Isomorphous. ] 1. A substance which is similar to another in crystalline form and composition. [ 1913 Webster ]

2. (Biol.) An animal, plant, or group having superficial similarity to another, although phylogenetically different. [ Webster 1913 Suppl. ]

a. 1. Isomorphous. [ 1913 Webster ]

2. (Biol.) Alike in form; exhibiting isomorphism. [ Webster 1913 Suppl. ]

3. Of or pertaining to sets related by an isomorphism. [ PJC ]

n. [ Cf. F. isomorphisme. ] 1. (Crystallog.) A similarity of crystalline form between substances of similar composition, as between the sulphates of barium (BaSO4) and strontium (SrSO4). It is sometimes extended to include similarity of form between substances of unlike composition, which is more properly called homœomorphism.

2. (Math.) A one-to-one mapping of one set onto another set which preserves the relations between the elements of the domains of the sets. [ PJC ]

a. [ Iso- + -morphous. ] Having the quality of isomorphism. [ 1913 Webster ]