collateral

adjective

descended from a common ancestor but through different lines
“cousins are collateral relatives”
indirect
situated or running side by side
“collateral ridges of mountains”
accompany, concomitant
“collateral target damage from a bombing run”
serving to support or corroborate
“collateral evidence”
confirmingconfirmativeconfirmatorycorroborativecorroboratorysubstantiatingsubstantiativeverifying

noun