chief petty officer noun3 •(Canada, Navy) A warrant officer belonging to one of the two classes of chief petty officer: chief petty officer first class and chief petty officer second class. •(UK, Navy) A non-commissioned officer in the Royal Navy, ranking above petty officer and below warrant officer class 2. •(US, Navy) A non-commissioned officer in the United States Navy and United States Coast Guard, ranking above petty officer first class and below senior chief petty officer. formschief petty officers