microcephalic vs microcephalous

microcephalic and microcephalous both are adjectives.

Word	Noun	Adjective	Verb	Adverb
microcephalic	No	Yes	No	No
microcephalous	No	Yes	No	No

As adjectives, microcephalic and microcephalous are synonyms defined as:

microcephalic and microcephalous: having an abnormally small head and underdeveloped brain

Other synonyms of microcephalic include nanocephalic.

microcephalic (adjective)	microcephalous (adjective)
having an abnormally small head and underdeveloped brain	having an abnormally small head and underdeveloped brain