microcephalus vs nanocephaly

microcephalus and nanocephaly both are nouns.

Word	Noun	Adjective	Verb	Adverb
microcephalus	Yes	No	No	No
nanocephaly	Yes	No	No	No

As nouns, microcephalus and nanocephaly are synonyms defined as:

microcephalus and nanocephaly: an abnormally small head and underdeveloped brain

Other synonyms of microcephalus include microcephaly.

microcephalus (noun)	nanocephaly (noun)
an abnormally small head and underdeveloped brain	an abnormally small head and underdeveloped brain