Stagnate rhymes with:
designate, impregnate, agglutinate, alienate, assassinate, caffeinate, carbonate, chlorinate, concatenate, contaminate, cross-pollinate, culminate, decaffeinate, decontaminate, denominate, designate, determinate, detonate, discriminate, disseminate, dominate, donate, eliminate, emanate, exterminate, fascinate, fulminate, germinate, halogenate, hibernate, hydrogenate, hyphenate, impersonate, impregnate, incriminate, inseminate, insubordinate, isocyanate, italianate, latinate, marinate, opinionate, originate, oxygenate, pollinate, polychlorinate, predominate, procrastinate, reincarnate, rejuvenate, renominate, resonate, ruminate, self-pollinate, subordinate, terminate, titanate, urinate
Stagnate sounds like:
stagehand, stagnant, stagnated, stichnoth, stigmata