The Collaborative International Dictionary of English v.0.48:

Whooping \Whoop"ing\,
   a. & n. from Whoop, v. t.
   [1913 Webster]

   Whooping cough (Med.), a violent, convulsive cough,
      returning at longer or shorter intervals, and consisting
      of several expirations, followed by a sonorous
      inspiration, or whoop; chin cough; hooping cough.
      --Dunglison.

   Whooping crane (Zool.), a North American crane (Crus
      Americana) noted for the loud, whooplike note which it
      utters.

   Whooping swan (Zool.), the whooper swan. See the Note under
      Swan.
      [1913 Webster]

WordNet (r) 3.0 (2006):

whooping cough
    n 1: a disease of the respiratory mucous membrane [syn:
         whooping cough, pertussis]