appurtenant
1. [ adjective ] relating to something that is added but is not essential
Synonyms: adjunct ancillary adjuvant auxiliary subsidiary accessory
Examples:

"an ancillary pump" "an adjuvant discipline to forms of mysticism" "The mind and emotions are auxilliary to each other"

Related terms: supportive
Similar spelling:   appurtenance
  appurtenances
  apartment
  aperture
  apportionable
  apportion
  appertain
  apartheid