isogon

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A polygon whose angles are equal.

from The Century Dictionary.

• noun In mathematics, a figure whose angles are equal.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun mathematics An equiangular polygon.
• noun cartography, meteorology A line of equal or constant wind direction on a graph or chart, such as a weather map.
• noun cartography, navigation A line of equal or constant magnetic declination on a chart; an isogonic line.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun an equiangular polygon