Source : Webster's Revised Unabridged Dictionary (1913)

Echo \Ech"o\, v. t. [imp. & p. p. {Echoed}; p. pr. & vb. n.
   {Echoing}. -- 3d pers. sing. pres. {Echoes}.]
   1. To send back (a sound); to repeat in sound; to
      reverberate.

            Those peals are echoed by the Trojan throng.
                                                  --Dryden.

            The wondrous sound Is echoed on forever. --Keble.

   2. To repeat with assent; to respond; to adopt.

            They would have echoed the praises of the men whom
            they ?nvied, and then have sent to the newspaper
            anonymous libels upon them.           --Macaulay.

Source : WordNet®

echoing
     adj : (of sounds) repeating by reflection; "a hotel with echoing
           halls" [syn: {echoing(a)}, {reechoing}]