Meltdown rhymes with:
piltdown, blastdown, countdown, letdown, piltdown, putdown, shootdown, shutdown, writedown, ashdown, blastdown, breakdown, clampdown, closedown, comedown, countdown, crackdown, drawdown, godown, hillsdown, hoedown, knockdown, lansdowne, letdown, lockdown, lowdown, markdown, piltdown, putdown, rundown, shakedown, shootdown, showdown, shutdown, slowdown, southdown, sundown, touchdown, turndown, underdown, writedown
Meltdown sounds like:
malathion, malden, malleton, maulden, mauldin, mealtime, melatonin, meldon, melton, militiamen, milton, molden, molten, molton, moulden, moulton, muldoon, muldowney, multnomah