clean' bill' of health'
1. a certificate of health attesting the lack of a contagious disease, as on a ship.
2. an assurance, as by a doctor, that one is in good health.
3. Also,clean' bill'.an assurance, esp. an official verdict by a committee, that a group or an individual has proved, under investigation, to be morally sound, fit for office, etc.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.