The Collaborative International Dictionary of English v.0.48:

Continence \Con"ti*nence\, Continency \Con"ti*nen*cy\, n. [F.
   continence, L. continentia. See Continent, and cf.
   Countenance.]
   1. Self-restraint; self-command.
      [1913 Webster]

            He knew what to say; he knew also, when to leave
            off, -- a continence which is practiced by few
            writers.                              --Dryden.
      [1913 Webster]

   2. The restraint which a person imposes upon his desires and
      passions; the act or power of refraining from indulgence
      of the sexual appetite, esp. from unlawful indulgence;
      sometimes, moderation in sexual indulgence.
      [1913 Webster]

            If they [the unmarried and widows] have not
            continency, let them marry.           --1 Cor. vii.
                                                  9 (Rev. Ver.
                                                  ).
      [1913 Webster]

            Chastity is either abstinence or continence:
            abstinence is that of virgins or widows; continence,
            that of married persons.              --Jer. Taylor.
      [1913 Webster]

   3. Uninterrupted course; continuity. [Obs.] --Ayliffe.
      [1913 Webster]

WordNet (r) 3.0 (2006):

continency
    n 1: the exercise of self constraint in sexual matters [syn:
         continence, continency]