Definition of pendecagon in English:

pendecagon

noun

Geometry
rare
  • A plane figure having fifteen straight sides and fifteen angles; a quindecagon.

Origin

Late 17th century; earliest use found in William Alingham (fl. 1694–1710). Apparently irregularly from pen- (in ancient Greek πέντε five: see penta-) + decagon. Compare post-classical Latin pentedecagonum, Hellenistic Greek πεντεκαιδεκάγωνον.

Pronunciation

pendecagon

/pɛnˈdɛkəɡ(ə)n//pɛnˈdɛkəɡɒn/