Pronunciation: (chēf),[key] —n. 1. the head or leader of an organized body of people; the person highest in authority: the chief of police. 2. the head or ruler of a tribe or clan: an Indian chief. 3. (cap.) U.S. Army.a title of some advisers to the Chief of Staff, who do not, in most instances, command the troop units of their arms or services: Chief of Engineers; Chief Signal Officer. 4. Informal.boss or leader: We'll have to talk to the chief about this. 5. Heraldry. a. the upper area of an escutcheon.
b. an ordinary occupying this area.
6. in chief, a. in the chief position; highest in rank (used in combination): editor in chief; commander in chief. b. Heraldry.in the upper part of an escutcheon.
—adj. 1. highest in rank or authority: the chief priest; the chief administrator. 2. most important; principal: his chief merit; the chief difficulty.