Source : Webster's Revised Unabridged Dictionary (1913)

Whisper \Whis"per\, v. i. [imp. & p. p. {Whispered}; p. pr. &
   vb. n. {Whispering}.] [AS. hwisprian; akin to G. wispern,
   wispeln, OHG. hwispal?n, Icel. hv[=i]skra, Sw. hviska, Dan.
   hviske; of imitative origin. Cf. {Whistle}.]
   1. To speak softly, or under the breath, so as to be heard
      only by one near at hand; to utter words without sonant
      breath; to talk without that vibration in the larynx which
      gives sonorous, or vocal, sound. See {Whisper}, n.

   2. To make a low, sibilant sound or noise.

            The hollow, whispering breeze.        --Thomson.

   3. To speak with suspicion, or timorous caution; to converse
      in whispers, as in secret plotting.

            All that hate me whisper together against me. --Ps.
                                                  xli. 7.

Whispering \Whis"per*ing\,
   a. & n. from {Whisper}. v. t.

   {Whispering gallery}, or {Whispering dome}, one of such a
      form that sounds produced in certain parts of it are
      concentrated by reflection from the walls to another part,
      so that whispers or feeble sounds are audible at a much
      greater distance than under ordinary circumstances.

Source : WordNet®

whispering
     adj : making a low continuous indistinct sound; "like murmuring
           waves"; "susurrant voices" [syn: {murmuring}, {susurrant}]

whispering
     n 1: the light noise like the noise of silk clothing or leaves
          blowing in the wind [syn: {rustle}, {rustling}, {whisper}]
     2: speaking softly without vibration of the vocal cords [syn: {whisper},
         {susurration}]