Pentagon

n.

1.

(Geom.) A plane figure having five angles, and, consequently, five sides; any figure having five angles. Regular pentagon a pentagon in which the angles are all equal, and the sides all equal.

Noun	1.	Pentagon - a government building with five sides that serves as the headquarters of the United States Department of Defense
	2.	Pentagon - the United States military establishment
	3.	pentagon - a five-sided polygon

polygon, polygonal shape