1historical In plural (in form Macrocephali). A supposed Asian or Scythian tribe or people who characteristically had unusually long heads; (in singular) a member of this tribe. See long head .
A fetus with macrocephaly (now rare, perhaps obsolete); macrocephaly; an instance of this.
Late 16th century; earliest use found in John Banister (1532/3–?1610), surgeon. From classical Latin macrocephalus (in Macrocephalī, plural, name of a tribe (Pliny)) from ancient Greek μακροκέϕαλος long-headed from μακρός + -κέϕαλος.