D defs.my
Entry 3 senses Webster, 1913

Peripheral

/pẽr-ĭf'-ẽr-əl/ · Pe·riph·er·al · IPA /pəˈɹɪf(ə)ɹ(ə)l/
01 a. Of or pertaining to a periphery; constituting a periphery; peripheric.
  1. 1.
    Of or pertaining to a periphery; constituting a periphery; peripheric.
  2. 2.
    External; away from the center; on or near the surface; as, the peripheral portion of the nervous system.(Anat.)
  3. 3.
    Pertaining to minor, unimportant, superficial, or irrelevant aspects of the matter in question; as, peripheral isssues are dealt with in the appendix.