Definition of trial:
(n) :
an
opportunity to test something out; a
test; appearance at judicial court
"they will perform the trials for the new equipment next week."
(adj) :
pertaining to a trial or test; attempted on a provisional or experimental basis
(v) :
to carry out a series of
tests on (a new product, procedure etc.) before marketing or implementing it; to try out (a new player) in a sports team
"the warning system was extensively trialled before being fitted to all our vehicles."