The Collaborative International Dictionary of English v.0.48:

Recurrence \Re*cur"rence\ (r?*k?r"rens), Recurrency
\Re*cur"ren*cy\ (-ren*s?), n. [Cf. F. r['e]currence.]
   The act of recurring, or state of being recurrent; return;
   resort; recourse.
   [1913 Webster]

         I shall insensibly go on from a rare to a frequent
         recurrence to the dangerous preparations. --I. Taylor.
   [1913 Webster]

WordNet (r) 3.0 (2006):

recurrence
    n 1: happening again (especially at regular intervals); "the
         return of spring" [syn: recurrence, return]