Fattened rhymes with:
flattened, brightened, buttoned, cottoned, disheartened, enlightened, flattened, frightened, heartened, heightened, heistand, hestand, hiestand, lightened, montand, predestined, shortened, smartened, straightened, sweetened, threatened, tightened, unbuttoned, unenlightened
Fattened sounds like:
fifteenth, footnote, footnoted