The Collaborative International Dictionary of English v.0.48:

Stertorous \Ster"to*rous\ (st[~e]r"t[-o]*r[u^]s), a. [L.
   stertere to snore: cf. F. stertoreux.]
   Characterized by a deep snoring, which accompanies
   inspiration in some diseases, especially apoplexy; hence,
   hoarsely breathing; snoring.
   [1913 Webster]

         Burning, stertorous breath that hurt her cheek. --Mrs.
                                                  Browning.
   [1913 Webster]

         The day has ebbed away, and it is night in his room,
         before his stertorous breathing lulls.   --Dickens.
   [1913 Webster]

WordNet (r) 3.0 (2006):

stertorous
    adj 1: of breathing having a heavy snoring sound