The Collaborative International Dictionary of English v.0.48:

Loathe \Loathe\ (l[=o][th]), v. t. [imp. & p. p. Loathed
   (l[=o][th]d); p. pr. & vb. n. Loathing.] [AS. l[=a][eth]ian
   to hate. See Loath.]
   1. To feel extreme disgust at, or aversion for.
      [1913 Webster]

            Loathing the honeyed cakes, I Ionged for bread.
                                                  --Cowley.
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   2. To dislike greatly; to abhor; to hate; to detest.
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            The secret which I loathe.            --Waller.
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            She loathes the vital sir.            --Dryden.

   Syn: To hate; abhor; detest; abominate. See Hate.
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The Collaborative International Dictionary of English v.0.48:

Loathing \Loath"ing\, n.
   Extreme disgust; a feeling of aversion, nausea, abhorrence,
   or detestation.
   [1913 Webster]

         The mutual fear and loathing of the hostile races.
                                                  --Macaulay.
   [1913 Webster]

WordNet (r) 3.0 (2006):

loathing
    n 1: hate coupled with disgust [syn: abhorrence,
         abomination, detestation, execration, loathing,
         odium]

Moby Thesaurus II by Grady Ward, 1.0:

46 Moby Thesaurus words for "loathing":
   Anglophobia, Russophobia, abhorrence, abhorrent, abomination,
   allergy, antagonism, anti-Semitism, antipathy, averse to, aversion,
   bigotry, cold sweat, creeping flesh, despitefulness, detestation,
   disgust, disgusted, dislike, enmity, execration, hate, hating,
   hatred, horror, hostility, malevolence, malice, malignity,
   misandry, misanthropy, misogyny, mortal horror, nausea, odium,
   race hatred, racism, repugnance, repulsion, revulsion, shuddering,
   spite, spitefulness, vials of hate, vials of wrath, xenophobia