Rainiest rhymes with:
zaniest, funniest, skinniest, thorniest, 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, riskiest, ritziest, rustiest, scariest, sexiest, showiest, silliest, skimpiest, skinniest, sloppiest, smoggiest, sniffiest, stealthiest, steamiest, stickiest, thorniest, tiniest, trickiest, ugliest, wealthiest, worthiest, zaniest
Rainiest sounds like:
raincoat, ramstad, rancid, rancidity, ranged, ranked, ransacked, rearranged, reenact, reenacted, rehnquist, reinstate, reinstated, reinstitute, reinstituted, reminisced, renegade, reneged, renegotiate, renegotiated, renounced, renquist, renunciate, renuzit, ringed, ringgit, ringquist, ringside, ringstad, ringuette, ringwood, ronstadt, rummaged, runquist