1. Not of central importance
2. Of or relating to or of the nature of a periphery
3. On or near an edge or constituting an outer boundary

(Computer science) Devices connected by cable to the CPU of a computer; SYN. computer peripheral, peripheral device.
A device that is external to the CPU and main memory, i.e., printer, modem or terminal, but is connected by the appropriate electrical connections.
In computing, a device, such as a disk drive, printer, modem, or joystick, that is connected to a computer and is controlled by the computer’s microprocessor. Also called: peripheral device. See also console.