THESAURUS
declivitous
collapsing, deciduous, declined, declining, declivate, declivous, decurrent, descendant, descending, dipping, down, down-reaching, downcoming, downfalling, downgoing, downgrade, downhill, downsinking, downward, drooping, dropping, falling, inclining, leaning, oblique, on the descendant, on the downgrade, pitched, plummeting, plunging, sagging, setting, sinking, sloped, sloping, submerging, subsiding, tilted, tipped, tottering, tumbledown