Butterfat rhymes with:
acrobat, aerostat, aristocrat, autocrat, babysat, bobcat, brickbat, bundesrat, bureaucrat, carlstadt, caveat, chitchat, clarostat, compumat, copycat, d'etat, darmstadt, democrat, diplomat, doormat, eberstadt, eizenstat, estedat, farhat, format, habitat, inverlat, karstadt, kitcat, laundromat, lestat, muskrat, parmalat, placemat, plutocrat, polecat, pussycat, ronstadt, rosenblatt, technocrat, thermostat, thundercat, tomcat, urstadt, verhofstadt, wesat, wildcat, wombat, yediyat, ziggurat