Definition of Tidal wave

• an overwhelming manifestation of some emotion or phenomenon; "a tidal wave of nausea"; "the flood of letters hit him with the force of a tidal wave"; "a tidal wave of crime"
• an unusual (and often destructive) rise of water along the seashore caused by a storm or a combination of wind and high tide
• a wave resulting from the periodic flow of the tides that is caused by the gravitational attraction of the moon and sun