trial run vs trial

trial run and trial both are nouns.

Word	Noun	Adjective	Verb	Adverb
trial run	Yes	No	No	No
trial	Yes	No	No	No

As nouns, trial run and trial are synonyms defined as:

Other synonyms of trial run include test, tryout.

trial run (noun)	trial (noun)
trying something to find out about it	the act of testing something
	(law) the determination of a person's innocence or guilt by due process of law
	the act of undergoing testing
	trying something to find out about it
	an annoying or frustrating or catastrophic event
	(sports) a preliminary competition to determine qualifications