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):

continence
    n 1: the exercise of self constraint in sexual matters [syn:
         continence, continency]
    2: voluntary control over urinary and fecal discharge

Moby Thesaurus II by Grady Ward, 1.0:

111 Moby Thesaurus words for "continence":
   Encratism, Friday, Lenten fare, Platonic love, Pythagoreanism,
   Pythagorism, Rechabitism, Shakerism, Spartan fare, Stoicism,
   abnegation, abstainment, abstemiousness, abstention, abstinence,
   asceticism, avoidance, bachelordom, bachelorhood, bachelorism,
   bachelorship, banyan day, boundary, bounds, calm, calmness,
   celibacy, chasteness, chastity, confinement, conservatism,
   constraint, continency, control, cool, discipline, dispassion,
   eschewal, evenness, fast, fish day, fruitarianism, gentleness,
   golden mean, gymnosophy, happy medium, impartiality, intactness,
   judiciousness, juste-milieu, lenity, limit, limitation, maidenhead,
   maidenhood, meden agan, middle way, mildness, misogamy, misogyny,
   moderateness, moderation, moderationism, monachism, monasticism,
   nephalism, neutrality, nonviolence, nothing in excess, pacifism,
   plain living, prescription, proscription, prudence, purity,
   qualification, refraining, refrainment, repose, restrain,
   restraint, restriction, self-abnegation, self-control, self-denial,
   self-restraint, serenity, sexual abstinence, simple diet,
   single blessedness, single state, singleness, sobriety, spare diet,
   spinsterhood, stability, steadiness, teetotalism, temperance,
   temperateness, the pledge, total abstinence, tranquillity,
   unexcessiveness, unextravagance, unextremeness, unwed state,
   vegetarianism, via media, virgin state, virginity