The Collaborative International Dictionary of English v.0.48:

Pant \Pant\ (p[.a]nt), v. i. [imp. & p. p. Panted; p. pr. &
   vb. n. Panting.] [Cf. F. panteler to gasp for breath, OF.
   panteisier to be breathless, F. pantois out of breath; perh.
   akin to E. phantom, the verb prob. orig. meaning, to have the
   nightmare.]
   1. To breathe quickly or in a labored manner, as after
      exertion or from eagerness or excitement; to respire with
      heaving of the breast; to gasp.
      [1913 Webster]

            Pluto plants for breath from out his cell. --Dryden.
      [1913 Webster]

   2. Hence: To long eagerly; to desire earnestly; -- often used
      with for or after.
      [1913 Webster]

            As the hart panteth after the water brooks. --Ps.
                                                  xlii. 1.
      [1913 Webster]

            Who pants for glory finds but short repose. --Pope.
      [1913 Webster]

   3. To beat with unnatural violence or rapidity; to palpitate,
      or throb; -- said of the heart. --Spenser.
      [1913 Webster]

   4. To sigh; to flutter; to languish. [Poetic]
      [1913 Webster]

            The whispering breeze
            Pants on the leaves, and dies upon the trees.
                                                  --Pope.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

panting \panting\ n.
   The act or process of breathing heavily, usually after
   exertion.

   Syn: heaving.
        [WordNet 1.5]

   2. Any fabric used to make trousers.

   Syn: trousering.
        [WordNet 1.5]

The Collaborative International Dictionary of English v.0.48:

panting \panting\ adj.
   Breathing laboriously or convulsively.

   Syn: gasping, out-of-breath(predicate), pursy, short-winded,
        winded.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

panting
    n 1: breathing heavily (as after exertion) [syn: panting,
         heaving]
    2: any fabric used to make trousers [syn: panting,
       trousering]