Trouncing rhymes with:
announcing, bouncing, denouncing, mispronouncing, pouncing, pronouncing, renouncing, advancing, announcing, balancing, bensing, bouncing, commencing, condensing, conferencing, convincing, counterbalancing, dancing, denouncing, dispensing, distancing, duensing, enhancing, ensing, expensing, experiencing, fencing, financing, freelancing, glancing, influencing, lancing, lansing, lensing, licensing, mensing, mincing, mispronouncing, outdistancing, pouncing, prancing, pronouncing, rebalancing, referencing, refinancing, renouncing, rensing, rinsing, romancing, sansing, sensing, sentencing, sequencing, silencing, teleconferencing, toensing, unconvincing, videoconferencing, wincing
Trouncing sounds like:
tarnishing, transgenic, transience, transimage, transoceanic, transoms, tranzonic, truncheons