diligent
adjective
careful and using a lot of effort, or done in a careful and detailed
way
a diligent student
diligent work
Leo is very diligent in/about his work.
Their lawyer was extremely diligent in preparing their case.
The discovery was made after years of diligent research.
diligence noun [U]
She hoped that her diligence would be noticed at work.
The diligence with which the police conducted the investigation
was highly praised.
diligently adverb