The Collaborative International Dictionary of English v.0.48:

Stridor \Stri"dor\, n. [L., from stridere to make any harsh,
   grating, or creaking sound.]
   A harsh, shrill, or creaking noise. --Dryden.
   [1913 Webster]

WordNet (r) 3.0 (2006):

stridor
    n 1: a whistling sound when breathing (usually heard on
         inspiration); indicates obstruction of the trachea or
         larynx

Moby Thesaurus II by Grady Ward, 1.0:

34 Moby Thesaurus words for "stridor":
   acuteness, arguteness, atonalism, atonality, cacophony, clinker,
   creakiness, discord, discordance, discordancy, disharmony,
   dissonance, dissonancy, dissonant chord, flatness, highness,
   inharmoniousness, inharmony, off note, pipingness, reediness,
   screechiness, sharpness, shrillness, sour note, sourness,
   stridence, stridency, stridulousness, tunelessness,
   unharmoniousness, unmusicality, untunefulness, wolf