Collateral

1. noun

   a security pledged for the repayment of a loan

2. adjective

   descended from a common ancestor but through different lines

   “cousins are collateral relatives”

   Similar: indirect

3. adjective

   serving to support or corroborate

   “collateral evidence”

   Similar: confirmative, confirming, confirmatory, corroborative, corroboratory, substantiating, substantiative, validating, validatory, verificatory, verifying