What is "in chief"

Chief \Chief\ (ch[=e]n), n. [OE. chief, chef, OF. chief, F. chef, fr. L. caput head, possibly akin to E. head. Cf. Captain, Chapter]

1. The head or leader of any body of men; a commander, as of an army; a head man, as of a tribe, clan, or family; a person in authority who directs the work of others; the principal actor or agent.

2. The principal part; the most valuable portion.

   The chief of the things which should be utterly destroyed.
   --1 Sam. xv. 21

3. (Her.) The upper third part of the field. It is supposed to be composed of the dexter, sinister, and middle chiefs. In chief.

   1. At the head; as, a commander in chief.

   2. (Eng. Law) From the king, or sovereign; as, tenure in chief, tenure directly from the king.

      Syn: Chieftain; captain; general; commander; leader; head; principal; sachem; sagamore; sheik.

      Usage: Chief, chieftain, Commander, Leader. These words fluctuate somewhat in their meaning according to circumstances, but agree in the general idea of rule and authority. The term chief is now more usually applied to one who is a head man, leader, or commander in civil or military affairs, or holds a hereditary or acquired rank in a tribe or clan; as, the chief of police; the chief of an Indian tribe. A chieftain is the chief of a clan or tribe, or a military leader. A commander directs the movements of or has control over a body of men, as a military or naval force. A leader is one whom men follow, as in a political party, a legislative body, a military or scientific expedition, etc., one who takes the command and gives direction in particular enterprises.

n. (context legal English) A case "in chief" is the stage during trial in which the party with the burden of proof presents supporting evidence.