The Collaborative International Dictionary of English v.0.48:

Cult \Cult\ (k[u^]lt) n. [F. culte, L. cultus care, culture, fr.
   colere to cultivate. Cf. Cultus.]
   1. Attentive care; homage; worship.
      [1913 Webster]

            Every one is convinced of the reality of a better
            self, and of the cult or homage which is due to it.
                                                  --Shaftesbury.
      [1913 Webster]

   2. A system of religious belief and worship.
      [1913 Webster]

            That which was the religion of Moses is the
            ceremonial or cult of the religion of Christ.
                                                  --Coleridge.
      [1913 Webster]

   3. A system of intense religious veneration of a particular
      person, idea, or object, especially one considered
      spurious or irrational by traditional religious bodies;
      as, the Moonie cult.
      [PJC]

   4. The group of individuals who adhere to a cult (senses 2 or
      3).
      [PJC]

   5. A strong devotion or interest in a particular person, idea
      or thing without religious associations, or the people
      holding such an interest; as, the cult of James Dean; the
      cult of personality in totalitarian societies.
      [PJC]

WordNet (r) 3.0 (2006):

cult
    n 1: followers of an exclusive system of religious beliefs and
         practices
    2: an interest followed with exaggerated zeal; "he always
       follows the latest fads"; "it was all the rage that season"
       [syn: fad, craze, furor, furore, cult, rage]
    3: followers of an unorthodox, extremist, or false religion or
       sect who often live outside of conventional society under the
       direction of a charismatic leader
    4: a religion or sect that is generally considered to be
       unorthodox, extremist, or false; "it was a satanic cult"
    5: a system of religious beliefs and rituals; "devoted to the
       cultus of the Blessed Virgin" [syn: cult, cultus,
       religious cult]