Computer equipment, such as a printer, disk drive or modem. An extension of the adjective's meaning of marginal, on the periphery. Greek periphereia (circumference).

Pe*riph"er*al (?), a.

1.

Of or pertaining to a periphery; constituting a periphery; peripheric.

2. Anat.

External; away from the center; as, the peripheral portion of the nervous system.

© Webster 1913.