The Collaborative International Dictionary of English v.0.48:

Recur \Re*cur"\ (r?*k?r"), v. i. [imp. & p. p. Recurred
   (-k?rd"); p. pr. & vb. n. Recurring.] [L. recurrere; pref.
   re- re- + currere to run. See Current.]
   1. To come back; to return again or repeatedly; to come again
      to mind.
      [1913 Webster]

            When any word has been used to signify an idea, the
            old idea will recur in the mind when the word is
            heard.                                --I. Watts.
      [1913 Webster]

   2. To occur at a stated interval, or according to some
      regular rule; as, the fever will recur to-night.
      [1913 Webster]

   3. To resort; to have recourse; to go for help.
      [1913 Webster]

            If, to avoid succession in eternal existence, they
            recur to the "punctum stans" of the schools, they
            will thereby very little help us to a more positive
            idea of infinite duration.            --Locke.
      [1913 Webster]

   Recurring decimal (Math.), a circulating decimal. See under
      Decimal.

   Recurring series (Math.), an algebraic series in which the
      coefficients of the several terms can be expressed by
      means of certain preceding coefficients and constants in
      one uniform manner.
      [1913 Webster]

WordNet (r) 3.0 (2006):

recur
    v 1: happen or occur again; "This is a recurring story" [syn:
         recur, repeat]
    2: return in thought or speech to something [syn: recur, go
       back]
    3: have recourse to; "The government resorted to rationing meat"
       [syn: fall back, resort, recur]

Moby Thesaurus II by Grady Ward, 1.0:

38 Moby Thesaurus words for "recur":
   alternate, be here again, circle, come again, come and go,
   come around, come back, come round, come round again,
   come up again, continue, cycle, echo, go back, intermit,
   keep coming, occur often, oscillate, pulsate, pulse, react,
   reappear, reoccur, repeat, resound, resume, return, return to mind,
   reverberate, revert, revolve, roll around, rotate, turn, undulate,
   vibrate, wheel, wheel around