Webster’s Revised Unabridged Dictionary · 1913
Idiomorphous
Id′i·o·morph′ous, a. [Gr. ἰδιόμορφος of peculiar form; ἴδιος peculiar + μορφή form.] 1. Having a form of its own.
2. (Crystallog.) Apperaing in distinct crystals; — said of the mineral constituents of a rock.