-esiv adjective
Etymology: degress ion + -ive
: tending to descend or decrease:
a. : based on a plan of taxation in which the rate decreases as the base increases, the rate structure containing some degree of progression in the lower brackets and then tapering off until all income over a certain figure is taxed at the same rate
b. : relating to or characterized by burning (as of solid grains of smokeless powder) in which the surface decreases as the burning advances — opposed to progressive
• de·gres·sive·ly -sə̇vlē adverb