Source : Webster's Revised Unabridged Dictionary (1913)

Ebb \Ebb\, n. [AS. ebba; akin to Fries. ebba, D. eb, ebbe, Dan.
   & G. ebbe, Sw. ebb, cf. Goth. ibuks backward; prob. akin to
   E. even.]
   1. The reflux or flowing back of the tide; the return of the
      tidal wave toward the sea; -- opposed to {flood}; as, the
      boats will go out on the ebb.

            Thou shoreless flood which in thy ebb and flow
            Claspest the limits of morality!      --Shelley.

   2. The state or time of passing away; a falling from a better
      to a worse state; low state or condition; decline; decay.
      ``Our ebb of life.'' --Roscommon.

            Painting was then at its lowest ebb.  --Dryden.

   {Ebb and flow}, the alternate ebb and flood of the tide;
      often used figuratively.

            This alternation between unhealthy activity and
            depression, this ebb and flow of the industrial.
                                                  --A. T.
                                                  Hadley.