controversy vs contention

controversy and contention both are nouns.

Word	Noun	Adjective	Verb	Adverb
controversy	Yes	No	No	No
contention	Yes	No	No	No

As nouns, controversy and contention are synonyms defined as:

controversy and contention: a contentious speech act; a dispute where there is strong disagreement

Other synonyms of controversy include arguing, argument, contestation, disceptation, disputation, tilt.

controversy (noun)	contention (noun)
a contentious speech act; a dispute where there is strong disagreement	the act of competing as for profit or a prize
	a contentious speech act; a dispute where there is strong disagreement
	a point asserted as part of an argument