(1):
(n.) One who, or that which, directs; one who regulates, guides, or orders; a manager or superintendent.
(2):
(n.) A part of a machine or instrument which directs its motion or action.
(3):
(n.) One of a body of persons appointed to manage the affairs of a company or corporation; as, the directors of a bank, insurance company, or railroad company.
(4):
(n.) A slender grooved instrument upon which a knife is made to slide when it is wished to limit the extent of motion of the latter, or prevent its injuring the parts beneath.