Meaning

noun a security pledged for the repayment of a loan

adjective descended from a common ancestor but through different lines

adjective serving to support or corroborate

originRecorded since c.1378, from Old French, from Medieval Latin collaterālis, from Latin col- (“together with”) (a form of con-) + the stem of latus (“side”). By surface analysis, col- + lateral.

Etymology from Wiktionary, CC BY-SA 3.0