confirmatory
1. [ adjective ] serving to support or corroborate
Synonyms: confirmative confirming corroborative corroboratory substantiating substantiative validating validatory verificatory verifying collateral
Examples:

"collateral evidence"

Related terms: supportive
Similar spelling:   confirmative
  confirmation
  confirmable
  confirmed
  conform_to
  confirming
  conformation
  conformably
  comfortably