Source : Webster's Revised Unabridged Dictionary (1913)

Yelp \Yelp\, n.
   A sharp, quick cry; a bark. --Chaucer.

Yelp \Yelp\, v. i. [imp. & p. p. {Yelped}; p. pr. & vb. n.
   {Yelping}.] [OE. yelpen, [yogh]elpen, to boast, boast
   noisily, AS. gielpan, gilpan, gylpan; akin to OHG. gelph
   arrogant: cf. Icel. gj[=a]lpa to yelp. Cf. {Yap}.]
   1. To boast. [Obs.]

            I keep [care] not of armes for to yelpe. --Chaucer.

   2. To utter a sharp, quick cry, as a hound; to bark shrilly
      with eagerness, pain, or fear; to yaup.

            A little herd of England's timorous deer, Mazed with
            a yelping kennel of French curs?      --Shak.

            At the least flourish of a broomstick or ladle, he
            would fly to the door with a yelping precipitation.
                                                  --W. Irving.

Source : WordNet®

yelp
     n : a sharp high-pitched cry (especially by a dog) [syn: {yelping}]
     v : bark in a high-pitched tone; "the puppies yelped" [syn: {yip},
          {yap}]