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

Moby Thesaurus II by Grady Ward, 1.0:

54 Moby Thesaurus words for "stertorous":
   asthmatic, brassy, brazen, breathing, choked, coarse, cracked,
   croaking, croaky, dry, errhine, expiratory, gruff, guttural, harsh,
   harsh-sounding, heaving, hoarse, huffing, husky, inspiratory,
   metallic, nasal, panting, pneumonic, puffing, pulmonary, pulmonic,
   ragged, raucid, raucous, respiratory, rhinal, rough, roupy, rude,
   sneezy, sniffling, sniffly, sniffy, snoring, snorting, snuffling,
   snuffly, snuffy, squawking, squawky, sternutatory, strangled,
   thick, throaty, tinny, wheezing, wheezy