showdown vs confrontation

showdown and confrontation both are nouns.

Word	Noun	Adjective	Verb	Adverb
showdown	Yes	No	No	No
confrontation	Yes	No	No	No

As nouns, showdown and confrontation are synonyms defined as:

Other synonyms of showdown include encounter, face-off.

showdown (noun)	confrontation (noun)
a hostile disagreement face-to-face	the act of hostile groups opposing each other
	a focussed comparison; bringing together for a careful comparison
	a hostile disagreement face-to-face
	a bold challenge
	discord resulting from a clash of ideas or opinions