Thorniest rhymes with:
funniest, rainiest, skinniest, tiniest, zaniest, angriest, atheist, bloodiest, blotchiest, blowiest, busiest, cheeriest, chilliest, craziest, deadliest, dirtiest, earliest, easiest, fanciest, flashiest, flightiest, flimsiest, fluffiest, foggiest, friendliest, funniest, grooviest, handiest, happiest, hardiest, heartiest, heaviest, heftiest, jolliest, juiciest, junkiest, laziest, likeliest, lobbyist, luckiest, mightiest, nastiest, noisiest, prettiest, raciest, rainiest, riskiest, ritziest, rustiest, scariest, sexiest, showiest, silliest, skimpiest, skinniest, sloppiest, smoggiest, sniffiest, stealthiest, steamiest, stickiest, tiniest, trickiest, ugliest, wealthiest, worthiest, zaniest
Thorniest sounds like:
tarnished, thermostat, thronged, tornquist, tourniquet, tournquist, transact, transacted, transect, transected, transit, transited, treurnicht, trinket, trounced, truncate, truncated, turncoat, turnquest, turnquist