Countdown rhymes with:
blastdown, letdown, meltdown, piltdown, putdown, shootdown, shutdown, writedown, ashdown, blastdown, breakdown, clampdown, closedown, comedown, crackdown, drawdown, godown, hillsdown, hoedown, knockdown, lansdowne, letdown, lockdown, lowdown, markdown, meltdown, piltdown, putdown, rundown, shakedown, shootdown, showdown, shutdown, slowdown, southdown, sundown, touchdown, turndown, underdown, writedown
Countdown sounds like:
camden, canadian, canadienne, candyman, canteen, cantin, cantina, canton, cantone, centanni, centeno, centime, centum, chandon, chinatown, cognition, comden, comedian, comedienne, comedown, commendation, committeeman, commotion, commutation, condemn, condition, condom, condominium, condon, condone, connotation, contain, contini, contino, continue, continuum, cosentino