parallelogram vs tetragon

parallelogram and tetragon both are nouns.

Word	Noun	Adjective	Verb	Adverb
parallelogram	Yes	No	No	No
tetragon	Yes	No	No	No

As nouns, tetragon is a hypernym of parallelogram; that is, tetragon is a word with a broader meaning than parallelogram:

parallelogram: a quadrilateral whose opposite sides are both parallel and equal in length
tetragon: a four-sided polygon

Other hypernyms of parallelogram include quadrangle, quadrilateral.

parallelogram (noun)	tetragon (noun)
a quadrilateral whose opposite sides are both parallel and equal in length	a four-sided polygon