Definition of "Trial" :

noun: the act of testing something

"In the experimental trials the amount of carbon was measured separately."

noun: the act of undergoing testing

"Candidates must compete in a trial of skill."

noun: (law) the determination of a person's innocence or guilt by due process of law

"He had a fair trial and the jury found him guilty."

noun: trying something to find out about it

"A sample for ten days free trial."

noun: an annoying or frustrating or catastrophic event

"His mother-in-law's visits were a great trial for him."

noun: (sports) a preliminary competition to determine qualifications

"The trials for the semifinals began yesterday."