Tidal \Tid"al\, a. Of or pertaining to tides; caused by tides; having tides; periodically rising and falling, or following and ebbing; as, tidal waters.

The tidal wave of deeper souls Into our inmost being rolls, And lifts us unawares Out of all meaner cares. --Longfellow.

Tidal air (Physiol.), the air which passes in and out of the lungs in ordinary breathing. It varies from twenty to thirty cubic inches.

Tidal basin, a dock that is filled at the rising of the tide.

Tidal wave.
   (a) See Tide wave, under Tide. Cf. 4th Bore.
   (b) A vast, swift wave caused by an earthquake or some extraordinary combination of natural causes. It rises far above high-water mark and is often very destructive upon low-lying coasts.

Source: Webster's Revised Unabridged Dictionary (1913)