Definition of microcephalus in US English:

microcephalus

noun

  • 1Medicine and Physical Anthropology. A person with microcephaly; = "microcephalic". Now rare.

  • 2Medicine= "microcephaly".

Origin

Mid 19th century; earliest use found in Robley Dunglison (1798–1869), physician and medical writer. From scientific Latin microcephalus, lit. ‘small-headed’ (used as a specific epithet in zoology and botany from 1775) or its etymon ancient Greek μικροκέϕαλος small-headed from μικρο- + -κεϕαλος.