Here's what rhymes with tumultueux.
no so know go though low show co blow pro row tho fo foe ho lo bo doe dough mo po ro toe wo woe tow yo beau bio ceux faut goe hoe jo ko sew soe vo beaux cho dau mow noe roe sho tuo yeux zo bro rho trow whoa doh below ago flow grow radio slow snow throw glow quo audio fro crow thro nouveau uno aliquot dicho floe rodeo topos dunno stow throe trousseau sloe tarot turbot kayo matzoh pekoe trousseaux borzoi schmo resew schmoe although ratio plateau studio undergo bestow chateau hello patio calico polio propos tableau aglow apropos outgrow tableaux chateaux plateaux chapeau kapok oleo undertow deathblow regrow bandeau gateau chapeaux fatso gateaux romeo tallyho embryo buffalo folio indigo portico stereo dynamo forego forgo politico vertigo cameo domino escrow medico mistletoe siglo spatio afterglow adagio piccolo foreknow pompano mustachio microdot moustachio overthrow overflow bungalow presidio oregano pistachio overgrow portfolio archipelago pianissimo generalissimo impresario braggadocio