The Collaborative International Dictionary of English v.0.48:

Repel \Re**pel"\ (r?-p?l"), v. t. [imp. & p. p. Repelled
   (-p?ld"); p. pr. & vb. n. Repelling.] [L. repellere,
   repulsum; pref. re- re- + pellere to drive. See Pulse a
   beating, and cf. Repulse, Repeal.]
   1. To drive back; to force to return; to check the advance
      of; to repulse as, to repel an enemy or an assailant.
      [1913 Webster]

            Hippomedon repelled the hostile tide. --Pope.
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            They repelled each other strongly, and yet attracted
            each other strongly.                  --Macaulay.
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   2. To resist or oppose effectually; as, to repel an assault,
      an encroachment, or an argument.
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            [He] gently repelled their entreaties. --Hawthorne.
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   Syn: Tu repulse; resist; oppose; reject; refuse.
        [1913 Webster]

WordNet (r) 3.0 (2006):

repelling
    adj 1: highly offensive; arousing aversion or disgust; "a
           disgusting smell"; "distasteful language"; "a loathsome
           disease"; "the idea of eating meat is repellent to me";
           "revolting food"; "a wicked stench" [syn: disgusting,
           disgustful, distasteful, foul, loathly,
           loathsome, repellent, repellant, repelling,
           revolting, skanky, wicked, yucky]

Moby Thesaurus II by Grady Ward, 1.0:

30 Moby Thesaurus words for "repelling":
   antigravity, awful, centrifugal force, diamagnetic, diamagnetism,
   disaffinity, dreadful, forbidding, foul, frightful, ghastly,
   grisly, gruesome, hideous, horrible, horrid, loathsome,
   magnetic repulsion, mutual repulsion, of opposite polarity,
   offensive, polarization, repellence, repellency, repellent,
   repugnant, repulsion, repulsive, revolting, terrible