To try out or test something; to put something to the test to check its performance or effect. Can also mean testing a person or method.
新しいアプリをスマホに入れて、機能を試してみた。
I installed a new app on my phone and tried out its features.
効果を確かめるために小さな範囲で試すことにした。
We decided to test it on a small scale to verify the effects.
彼は友人の忠誠心を試すようなことを言ってしまった。
He said something that amounted to testing his friend's loyalty.