The Collaborative International Dictionary of English v.0.48:

Asthma \Asth"ma\ (?; 277), n. [Gr. ? short-drawn breath, fr. ?
   to blow, for ?: cf. Skr. v[=a], Goth. waian, to blow, E.
   wind.] (Med.)
   A disease, characterized by difficulty of breathing (due to a
   spasmodic contraction of the bronchi), recurring at
   intervals, accompanied with a wheezing sound, a sense of
   constriction in the chest, a cough, and expectoration.
   [1913 Webster]

WordNet (r) 3.0 (2006):

asthma
    n 1: respiratory disorder characterized by wheezing; usually of
         allergic origin [syn: asthma, asthma attack, bronchial
         asthma]