competition vs contention

competition and contention both are nouns.

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

As nouns, competition and contention are synonyms defined as:

competition and contention: the act of competing as for profit or a prize

Other synonyms of competition include rivalry.

competition (noun)	contention (noun)
the act of competing as for profit or a prize	the act of competing as for profit or a prize
an occasion on which a winner is selected from among two or more contestants	a contentious speech act; a dispute where there is strong disagreement
the contestant you hope to defeat	a point asserted as part of an argument
a business relation in which two parties compete to gain customers