the head or leader of an organized body of people; the person highest in authority: the chief of police.
the head or ruler of a tribe or clan: an Indian chief.
(initial capital letter) 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.
Informal. boss or leader: We'll have to talk to the chief about this.
Heraldry. the upper area of an escutcheon. an ordinary occupying this area.