› honest and fair, or showing that you have done nothing illegal or morally wrong: a clean record/report/license Job applicants must have a clean commercial driver's license. He said the campaign's priorities will be "education and clean government."
› ENVIRONMENT free of, or producing no harmful chemicals or substances: clean energy/fuel/technology clean energy from renewable sources such as solar and wind power clean air/water/soil
have clean hands informal › to have never been involved in a dishonest or illegal activity: An audit proved that neither company had clean hands when it came to reporting profits.