Definition
A diligent person works with care and persistence — not in bursts of inspiration, but steadily, day after day, with attention to detail. Diligence is the quality of the student who reviews a little every evening, the researcher who checks every source, the employee who follows through. The word praises both the effort and the conscientiousness behind it: diligent work is thorough as well as hard.
Examples
- A diligent student reviews vocabulary a little every day instead of cramming before the exam.
- The investigators were diligent in tracking down every witness to the incident.
- Years of diligent practice carried her from the back row of the orchestra to first violin.
Synonyms
industrious · hardworking · conscientious · assiduous · persistent
In TOEFL & IELTS
A high-frequency adjective in TOEFL/IELTS speaking topics about study habits, work, and success — 'a diligent student/worker' is a ready-made collocation worth memorizing. In reading passages it often characterizes scientists and historical figures. Note the noun form 'diligence' and the common phrase 'due diligence' in business contexts.