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