Source : Webster's Revised Unabridged Dictionary (1913)

Moan \Moan\ (m[=o]n), v. i. [imp. & p. p. {Moaned} (m[=o]nd); p.
   pr. & vb. n. {Moaning}.] [AS. m[=ae]nan to moan, also, to
   mean; but in the latter sense perh. a different word. Cf.
   {Mean} to intend.]
   1. To make a low prolonged sound of grief or pain, whether
      articulate or not; to groan softly and continuously.

            Unpitied and unheard, where misery moans. --Thomson.

            Let there bechance him pitiful mischances, To make
            him moan.                             --Shak.

   2. To emit a sound like moan; -- said of things inanimate;
      as, the wind moans.

Source : WordNet®

moaning
     adj : making low inarticulate sound as e.g. of pain or sorrow;
           "the groaning wounded"; "moaning sounds in her sleep"
           [syn: {groaning}]