English definition of “trial”
/traɪəl/ noun [C, U]
LAW › a legal process to decide if someone is guilty of a crime: The two men are now on trial for attempted murder. He will be taken to the US to stand trial.
TEST › a test of something new to find out if it is safe, works correctly, etc: The drug is currently undergoing clinical trials.
trial and error › a way of learning the best way to do something by trying different methods: There aren't any instructions with it - it's just a matter of trial and error.