Fattening rhymes with:
battening, flattening, battening, brightening, captaining, disheartening, enlightening, flattening, frightening, heartening, heightening, lightening, shortening, smartening, straightening, sweetening, threatening, tightening
Fattening sounds like:
fading, fadness, fathoms, feeding, feedings, fetting, feuding, fidenas, fiefdoms, fifteens, fitness, fitting, fittings, footing, footings, fthenakis, futons