- the head member of the staff officers of a division or higher unit in the armed forces, or of the Departments of the Army or Air Force
- the head of any staff; esp., the head of the physicians and surgeons of a hospital
chief of staffchief of staff
chief of staff
nounpl. chiefs of staff
- The ranking officer of the US Army or Air Force, responsible to the secretary of his or her branch and to the president.
- A senior military staff officer at the division level or higher.
- The highest-ranking staff member at an institution or organization.