Source : Webster's Revised Unabridged Dictionary (1913)

Tautological \Tau`to*log"ic*al\, a. [Cf. F. tautologique.]
   Involving tautology; having the same signification; as,
   tautological expression. -- {Tau`to*log"ic*al*ly}, adv.

   {Tautological echo}, an echo that repeats the same sound or
      syllable many times.