The Collaborative International Dictionary of English v.0.48:

Stupor \Stu"por\, n. [L., from stupere to be struck senseless.]
   1. Great diminution or suspension of sensibility; suppression
      of sense or feeling; lethargy.
      [1913 Webster]

   2. Intellectual insensibility; moral stupidity; heedlessness
      or inattention to one's interests.
      [1913 Webster]

WordNet (r) 3.0 (2006):

stupor
    n 1: the feeling of distress and disbelief that you have when
         something bad happens accidentally; "his mother's death
         left him in a daze"; "he was numb with shock" [syn: daze,
         shock, stupor]
    2: marginal consciousness; "his grogginess was caused as much by
       exhaustion as by the blows"; "someone stole his wallet while
       he was in a drunken stupor" [syn: grogginess, stupor,
       stupefaction, semiconsciousness]

Moby Thesaurus II by Grady Ward, 1.0:

155 Moby Thesaurus words for "stupor":
   KO, abstraction, abulia, acedia, alienation, aloofness, amnesia,
   anesthesia, anxiety, anxiety equivalent, anxiety state, apathy,
   ataraxia, ataraxy, benumbedness, blackout, blah, blahs, boredom,
   catalepsy, cataplexy, catatonia, catatonic stupor, catatony, coma,
   comatoseness, compulsion, daydreaming, daze, dejection, depression,
   detachment, disinterest, dispassion, dream state, drowsiness,
   dullness, elation, emotionalism, encephalitis lethargica,
   enervation, ennui, euphoria, faint, fatigue, folie du doute, fugue,
   fugue state, grayout, heartlessness, heaviness, hebetude, high,
   hopelessness, hypnotic trance, hypochondria, hysteria, hysterics,
   inanimation, inappetence, indifference, inertia, inertness,
   insensibility, insouciance, jadedness, kayo, knockout,
   lack of appetite, lackadaisicalness, languidness, languishment,
   languor, languorousness, lassitude, laziness, lenitude, lentor,
   lethargicalness, lethargy, lifelessness, lipothymia, lipothymy,
   listlessness, mania, melancholia, mental distress, narcohypnosis,
   narcolepsy, narcoma, narcosis, narcotic stupor, narcotization,
   nirvana, nirvana principle, nod, nonchalance, nothingness,
   numbness, oblivion, obliviousness, obsession, oscitancy,
   passiveness, passivity, pathological indecisiveness, phlegm,
   phlegmaticalness, phlegmaticness, plucklessness, preoccupation,
   psychalgia, psychomotor disturbance, resignation, resignedness,
   reverie, satedness, sedation, semiconsciousness, senselessness,
   shock, sleep, sleepiness, sleeping sickness, sleepwalking, sloth,
   slothfulness, slowness, sluggishness, slumber, somnambulism,
   somnolence, sopor, soporifousness, spiritlessness, spunklessness,
   stupefaction, supineness, swoon, syncope, thanatosis, tic,
   torpidity, torpidness, torpitude, torpor, trance, twitching,
   unconcern, unconsciousness, unresponsiveness, weariness,
   withdrawal, withdrawnness, world-weariness