tantamount: [17] Tantamount means etymologically ‘amounting to as much’. It comes from an earlier verb tantamount ‘amount to as much as, be equal to’, which was a lexicalization of the Anglo-Norman expression tant amunter ‘amount to as much’. This was made up of tant ‘as much’, which came via Old French from Latin tantus, and amunter, ancestor of English amount. => amount, paramount[tantamount etymology, tantamount origin, 英语词源]