Definition of demonymic in English:

demonymic

Pronunciation /ˌdiːməˈnɪmɪk/

noun

rare Ancient Greek History
  • A personal name derived from that of the deme to which a citizen of ancient Attica belonged.

Origin

Late 19th century; earliest use found in John Edwin Sandys (1844–1922), classical scholar. From ancient Greek δῆμος people + -onymic.