"existing in two forms" (especially of crystals), 1801, from Greek dimorphos "of two forms," from di- (see di- (1)) + morphē "form, shape," a word of uncertain etymology.
Entries linking to dimorphous
di- 1
word-forming element of Greek origin meaning "two, double, twice, twofold," from Greek di-, shortened form of dis "twice," which is related to duo "two" and cognate with bi-, from PIE root *dwo- "two." In chemistry it indicates a compound containing two units of the element or radical to which it is prefixed.