From Longman Dictionary of Contemporary Englishdiligentdil‧i‧gent /ˈdɪlədʒənt/ adjective WORK HARDsomeone who is diligent works hard and is careful and thorough a diligent student —diligently adverb They worked diligently all morning. —diligence noun [uncountable]
Examples from the Corpus
diligent• As a pastor he was diligent and although iconoclastic, he defended the clergy against outside attack.• As an example of unconscious wealth Ely cited an obedient, diligent, and faithful son.• They have a powerful cultural drive to achieve, which makes them extremely diligent, effective and reliable workers.• It took some curious and diligent minds, and sometimes even some courage.• It is uncharacteristically diligent of a minister to seek precisely to understand what money spent will accomplish.• I know all of you are hardworking, diligent people, and I respect you for that.• After years of diligent research, he had concluded that this was the only copy still in existence.• The book required ten years of diligent research.• Tony is a very diligent student.Origin diligent (1300-1400) French Latin, present participle of diligere “to put high value on, love” 