Tsunami :  (noun)

1: a huge destructive wave (especially one caused by an earthquake) [syn: tidal wave]

apoplexy, billow, bore, breakers, breakup, cataclysm, chop, choppiness, chopping sea, climax, comb, comber, convulsion, diastrophism, dirty water, disaster, eagre, fit, gravity wave, ground swell, heave, heavy sea, heavy swell, lift, lop, overthrow, paroxysm, peak, popple, quake, riffle, ripple, rise, roll, roller, rough water, scend, sea, send, spasm, stroke, surf, surge, swell, temblor, tidal bore, tidal wave, tide wave, trough, undulation, upheaval, water wave, wave, wavelet, white horses, whitecaps,