Downside rhymes with:
burnside, ironside, mountainside, oceanside, alcide, backside, bayside, beachside, bedside, blindside, broadside, brookside, burnside, cambridgeside, cityside, countryside, curbside, dioxide, dockside, exide, fireside, fratricide, fungicide, garside, gartside, genocide, germicide, glucoside, glycoside, graveside, harborside, herbicide, hillside, homicide, infanticide, insecticide, ironside, ketcherside, lakeside, mountainside, oceanside, oxide, parkside, peroxide, pesticide, poolside, prophesied, ringside, riverside, roadside, seaside, silverside, southside, suicide, sunnyside, superoxide, underside, wayside, whiteside, woodside
Downside sounds like:
damaged, daminozide, danced, danstett, dehumanized, demonized, denounced, densest, density, dienst, diminished, donizetti, doomsday, downcast, downsized, downstate, dunked, dunst, dynasty