The Collaborative International Dictionary of English v.0.48:

Gulp \Gulp\, v. t. [imp. & p. p. Gulped; p. pr. & vb. n.
   Gulping.] [D. gulpen, cf. OD. golpe gulf.]
   To swallow eagerly, or in large draughts; to swallow up; to
   take down at one swallow.
   [1913 Webster]

         He does not swallow, but he gulps it down. --Cowper.
   [1913 Webster]

         The old man . . . glibly gulped down the whole
         narrative.                               --Fielding.
   [1913 Webster]

   To gulp up, to throw up from the stomach; to disgorge.
      [1913 Webster]

WordNet (r) 3.0 (2006):

gulping
    n 1: a spasmodic reflex of the throat made as if in swallowing
         [syn: gulp, gulping]
    2: the drinking of large mouthfuls rapidly [syn: gulping,
       swilling, guzzling]