The Collaborative International Dictionary of English v.0.48:

Wheeze \Wheeze\, v. i. [imp. & p. p. Wheezed; p. pr. & vb. n.
   Wheezing.] [OE. whesen, AS. hw[=e]san (cf. Icel. hv[ae]sa
   to hiss, Sw. hv[aum]sa, Dan. hv[ae]se); akin to AS. hw[=o]sta
   a cough, D. hoest, G. husten, OHG. huosto, Icel. h[=o]sti,
   Lith. kosti to cough, Skr. k[=a]s. [root]43. Cf. Husky
   hoarse.]
   To breathe hard, and with an audible piping or whistling
   sound, as persons affected with asthma. "Wheezing lungs."
   --Shak.
   [1913 Webster]

WordNet (r) 3.0 (2006):

wheezing
    adj 1: relating to breathing with a whistling sound [syn:
           asthmatic, wheezing, wheezy]

Moby Thesaurus II by Grady Ward, 1.0:

40 Moby Thesaurus words for "wheezing":
   asthmatic, breathing, breathless, effervescent, errhine,
   expiratory, fizzling, heaving, hissing, huffing, hushing,
   inspiratory, nasal, out of breath, panting, pneumonic, puffing,
   pulmonary, pulmonic, respiratory, rhinal, short-breathed,
   short-winded, sibilant, sissing, sizzling, sneezy, sniffing,
   sniffling, sniffly, sniffy, snoring, snorting, snuffling, snuffly,
   snuffy, sternutatory, stertorous, wheezy, winded