- having seven sides or angles.
Origin of heptagonal
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for heptagonal
Meshes regular or subregular, hexagonal, often intermingled with a variable number of pentagonal and heptagonal meshes.
Meshes subregular pentagonal (intermingled with single tetragonal, hexagonal, and heptagonal meshes).
The effect of a heptagonal stem on an octagonal base or plinth is certainly odd.Bell's Cathedrals: The Abbey Church of Tewkesbury
H. J. L. J. Mass