/tan"teuh mownt'/ , adj.
equivalent, as in value, force, effect, or signification: His angry speech was tantamount to a declaration of war.
[ 1635-45; adj. use of obs. n.: that which amounts to as much, itself n. use of obs. v.: to amount to as much tant amunter or It tanto montare to amount to as much. See TANTO, AMOUNT ]
Syn . See equal .