D defs.my
Entry 5 senses Webster, 1913

Controller

/kən-trōl'-ẽr/ · Con·trol·ler · IPA /kənˈtɹoʊlɚ/
01 n. One who, or that which, controls or restraines; one who has power or authority to regulate or control; one who governs.
  1. 1.
    One who, or that which, controls or restraines; one who has power or authority to regulate or control; one who governs.
    “The great controller of our fate Deigned to be man, and lived in low estate.” Dryden.
  2. 2.
    An officer appointed to keep a counter register of accounts, or to examine, rectify, or verify accounts.
  3. 3.
    An iron block, usually bolted to a ship's deck, for controlling the running out of a chain cable. The links of the cable tend to drop into hollows in the block, and thus hold fast until disengaged.(Naut.)
  4. 4.
    Any electric device for controlling a circuit or system;(Elec.)
  5. 5.
    A lever controlling the speed of an engine; -- applied esp. to the lever governing a throttle valve, as of a steam or gasoline engine, esp. on an automobile.(Mach.)