Heavyset rhymes with:
amagansett, ansett, asset, avocet, backset, exocet, handset, headset, inset, mediaset, mindset, morrisett, onset, outset, somerset, subset, sunset, typeset, videocassette
Heavyset sounds like:
habicht, hapgood, happiest, heaviest, heavyweight, hip-pocket, hippest, hobbyist, hobgood, hofstad, hopgood