'Peripheral' definitions:

Definition of 'peripheral'

From: WordNet
adjective
On or near an edge or constituting an outer boundary; the outer area; "Russia's peripheral provinces"; "peripheral suburbs" [ant: central]
adjective
Related to the key issue but not of central importance; "a peripheral interest"; "energy is far from a peripheral issue in the economy"; "peripheral issues"
noun
(computer science) electronic equipment connected by cable to the CPU of a computer; "disk drives and printers are important peripherals" [syn: peripheral, computer peripheral, peripheral device]

Definition of 'Peripheral'

From: GCIDE
  • Peripheral \Pe*riph"er*al\, a.
  • 1. Of or pertaining to a periphery; constituting a periphery; peripheric. [1913 Webster]
  • 2. (Anat.) External; away from the center; on or near the surface; as, the peripheral portion of the nervous system. [1913 Webster]
  • 3. Pertaining to minor, unimportant, superficial, or irrelevant aspects of the matter in question; as, peripheral isssues are dealt with in the appendix. [PJC] Peripheric