English

pentangular

From pent- + -angular, after pentangle.

Proto-Indo-European *h₂eng- ‘bend, curve’

…

Proto-Italic *angulos

Latin angulus ‘angle, corner’

Latin angulāris

Middle English angular

Today it means

adj Having five corners or angles.

Language periods are conventional ranges, not dates for this word.

Etymograph / pentangular