contestation vs polemic

contestation and polemic both are nouns.

Word	Noun	Adjective	Verb	Adverb
contestation	Yes	No	No	No
polemic	Yes	Yes	No	No

As nouns, polemic is a hyponym of contestation; that is, polemic is a word with a more specific, narrower meaning than contestation:

contestation: a contentious speech act; a dispute where there is strong disagreement
polemic: a controversy (especially over a belief or dogma)

Other hyponyms of contestation include argle-bargle, argy-bargy, firestorm, sparring, fight.

contestation (noun)	polemic (noun)
a contentious speech act; a dispute where there is strong disagreement	a controversy (especially over a belief or dogma)
	a writer who argues in opposition to others (especially in theology)

contestation (adjective)	polemic (adjective)
	of or involving dispute or controversy