The Collaborative International Dictionary of English v.0.48:

Chastity \Chas"ti*ty\, n. [F. chastet['e], fr. L. castitas, fr.
   castus. See Chaste.]
   1. The state of being chaste; purity of body; freedom from
      unlawful sexual intercourse.
      [1913 Webster]

            She . . . hath preserved her spotless chastity. --T.
                                                  Carew.
      [1913 Webster]

   2. Moral purity.
      [1913 Webster]

            So dear to heaven is saintly chastity,
            That, when a soul is found sicerely so
            A thousand liveried angels lackey her. --Milton.
      [1913 Webster]

   3. The unmarried life; celibacy. [Obs.] --Chaucer.
      [1913 Webster]

   4. (Literature & Art) Chasteness.
      [1913 Webster]

WordNet (r) 3.0 (2006):

chastity
    n 1: abstaining from sexual relations (as because of religious
         vows) [syn: chastity, celibacy, sexual abstention]
    2: morality with respect to sexual relations [syn: virtue,
       chastity, sexual morality]

Moby Thesaurus II by Grady Ward, 1.0:

102 Moby Thesaurus words for "chastity":
   Atticism, Encratism, Friday, Lenten fare, Pythagoreanism,
   Pythagorism, Rechabitism, Shakerism, Spartan fare, Stoicism,
   absoluteness, abstainment, abstemiousness, abstention, abstinence,
   appropriateness, asceticism, avoidance, banyan day, celibacy,
   chasteness, clarity, classicalism, classicism, clearness,
   comeliness, continence, correctness, defectlessness, dignity,
   directness, discrimination, distinction, ease, elegance, elegancy,
   eschewal, fast, faultlessness, felicitousness, felicity, finish,
   fish day, fittingness, flawlessness, flow, flowing periods,
   fluency, forbearance, fruitarianism, good taste, grace,
   gracefulness, gracility, guiltlessness, gymnosophy, immaculacy,
   immaculateness, impeccability, infallibility, innocence, limpidity,
   lucidity, maidenhead, maidenhood, naturalness, neatness, nephalism,
   pellucidity, perfection, perspicuity, plain living, plainness,
   polish, propriety, purity, refinement, refraining, refrainment,
   restraint, seemliness, self-restraint, sexual abstinence,
   simple diet, simplicity, sinlessness, smoothness, spare diet,
   spotlessness, stainlessness, straightforwardness, taintlessness,
   taste, tastefulness, teetotalism, terseness, the pledge,
   total abstinence, unaffectedness, vegetarianism, virginity,
   virtue