Source : Webster's Revised Unabridged Dictionary (1913)

Wail \Wail\, v. t. [Cf. Icel. val choice, velja to choose, akin
   to Goth. waljan, G. w["a]hlen.]
   To choose; to select. [Obs.] ``Wailed wine and meats.''
   --Henryson.

Wail \Wail\, v. t. [imp. & p. p. {Wailed}; p. pr. & vb. n.
   {Wailing}.] [OE. wailen, weilen, probably fr. Icel. v[ae]la;
   cf. Icel. v[ae], vei, woe, and E. wayment, also OE. wai, wei,
   woe. Cf. {Woe}.]
   To lament; to bewail; to grieve over; as, to wail one's
   death. --Shak.

Wail \Wail\, v. i.
   To express sorrow audibly; to make mournful outcry; to weep.

         Therefore I will wail and howl. --Micah i. 8.

Wail \Wail\, n.
   Loud weeping; violent lamentation; wailing. ``The wail of the
   forest.'' --Longfellow.

Source : WordNet®

wail
     n : a cry of sorrow and grief; "their pitiful laments could be
         heard throughout the ward" [syn: {lament}, {lamentation},
          {plaint}]
     v 1: emit long loud cries; "wail in self-pity"; "howl with
          sorrow" [syn: {howl}, {ululate}, {roar}, {yawl}]
     2: cry weakly or softly; "she wailed with pain" [syn: {whimper},
         {mewl}, {pule}]