concave polygon vs convex polygon

concave polygon and convex polygon both are nouns.

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

concave polygon (noun)	convex polygon (noun)
a polygon such that there is a straight line that cuts it in four or more points	a polygon such that no side extended cuts any other side or vertex; it can be cut by a straight line in at most two points