Definition of sexagon in US English:

sexagon

noun

Mathematics
rare
  • Hexagon.

Origin

Early 17th century; earliest use found in Aaron Rathborne (b. ?1572), land surveyor and author. Alteration of hexagon, after classical Latin sex six. Compare post-classical Latin sexagonus, Middle French sexagone, both in sense ‘hexagonal’.

Pronunciation

sexagon

/ˈɛksəɡ(ə)n/