dimorphic – occurring in two distinct forms

(Pronounced dai-mor-fik)

Note: Sexual dimorphism is the difference in form between individuals of different sex of the same species. 

To remember the definition of the word dimorphic, use the following mnemonic:

His feathers weren't dyed to look more terrific (dimorphic), they were naturally like that. The male peacock and the female peahen occur in two distinct forms. 

Examples of dimorphic in a sentence

There are numerous species of birds that are sexually dimorphic.

They only had subtle sexually dimorphic differences.

In some size dimorphic spiders, the female is the larger than the male.