![](http://image.absoluteastronomy.com/images//topicimages/p/pe/pentagon.gif)
Pentagon
WordNet
noun
(1) A government building with five sides that serves as the headquarters of the United States Department of Defense
(2) The United States military establishment
(3) A five-sided polygon
WiktionaryText
Proper noun
- the headquarters of the United States of America's Department of Defense.
Noun
- pentagon (a polygon with five sides and five angles)