reliable
adj. B1 Intermediate Oxford US //ɹiˈɫaɪəbəɫ// UK //ɹɪlˈaɪəbəl// re·li·able
adj. someone or something you can trust to do what they are supposed to do. If a person is like this, they always keep their promises.
adj. consistently performing well or behaving as expected; worthy of trust or confidence.
My car is old but it is still very reliable.
The manager is looking for a reliable assistant who can handle the office while she is traveling.
While the initial data seemed promising, the researchers needed a more reliable method of collection to ensure the results would hold up under peer review.
From rely + -able.
Usage
Typically used to describe people, machines, or information sources; often followed by the preposition 'for' or 'in'.