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.

Source : WordNet®

whispered
     adj : spoken in soft hushed tones (without vibrations of the vocal
           cords); "a long whispered conversation"