heptagon

[ hep-tuh-gon, -guh n ]

/ ˈhɛp təˌgɒn, -gən /

a polygon having seven angles and seven sides.

Origin of heptagon

First recorded in 1560–70, heptagon is from the Greek word heptágōnos seven-cornered. See hepta-, -gon

In the power room of the heptagon a hexan officer turned fiercely to another, who was offering advice.

Spacehounds of IPC |Edward Elmer Smith
There he and his fellows labored day after day learning every secret of every item of armament and equipment aboard the heptagon.

Spacehounds of IPC |Edward Elmer Smith
Any child can make a heptagon at once, notwithstanding Mr. Abbott calls it so difficult.

The Atlantic Monthly, Volume 5, No. 28, February, 1860 |Various
Heptagon, hep′ta-gon, n. a plane figure with seven angles and seven sides.

Chambers's Twentieth Century Dictionary (part 2 of 4: E-M) |Various

As that dazzling wall sprang into being, the sparkling green protection died from the walls of the heptagon.

Spacehounds of IPC |Edward Elmer Smith

heptagon

/ (ˈhɛptəɡən) /

a polygon having seven sides

heptagonal (hɛpˈtæɡənəl), adjective

heptagon

[ hĕp′tə-gŏn′ ]

A polygon having seven sides.