concave polygon vs polygon

concave polygon and polygon both are nouns.

Word	Noun	Adjective	Verb	Adverb
concave polygon	Yes	No	No	No
polygon	Yes	No	No	No

As nouns, polygon is a hypernym of concave polygon; that is, polygon is a word with a broader meaning than concave polygon:

concave polygon: a polygon such that there is a straight line that cuts it in four or more points
polygon: a closed plane figure bounded by straight sides

Other hypernyms of concave polygon include polygonal shape.

concave polygon (noun)	polygon (noun)
a polygon such that there is a straight line that cuts it in four or more points	a closed plane figure bounded by straight sides