controller: Meaning and Definition of

con•trol•ler

1. an employee, often an officer, of a business firm who checks expenditures, finances, etc.; comptroller.
2. a person who regulates, directs, or restrains.
3. a dispatcher.
4. a regulating mechanism; governor.
5. Also calledthe key component of a peripheral device, as a terminal, printer, or external storage unit, that contains the circuitry necessary to interpret and execute instructions fed into the device.