chief / chēf/ • n. 1. a leader or ruler of a people or clan: the chief of the village. ∎ the person with the highest rank in an organization: the chief of police. ∎ an informal form of address, esp. to someone of superior rank or status: it's quite simple, chief.2. Heraldry an ordinary consisting of a broad horizontal band across the top of the shield. ∎ the upper third of the field.• adj. most important: the chief reason for the spending cuts. ∎ having or denoting the highest rank or authority: the government's chief adviser.DERIVATIVES: chief·dom / -dəm/ n.chief·ship / -ˌship/ n.