Mid 17th century; earliest use found in Barrow's Euclide's Elements. Either from classical Latin polygōnuspolygon + -ous, or from polygon (or its etymon post-classical Latin polygonum) + -ous.
Definition of polygonous in US English:
polygonous
adjective
rare
Polygonal.
Origin
Mid 17th century; earliest use found in Barrow's Euclide's Elements. Either from classical Latin polygōnus polygon + -ous, or from polygon (or its etymon post-classical Latin polygonum) + -ous.