ADJECTIVE (3)

1. morally pure (especially not having experienced sexual intercourse);
- Example: "a holy woman innocent and chaste"

2. pure and simple in design or style;
- Example: "a chaste border of conventionalized flowers"

3. abstaining from unlawful sexual intercourse;

The Collaborative International Dictionary of English v.0.48:

Chaste \Chaste\ (ch[=a]st), a. [F. chaste, from L. castus pure,
   chaste; cf. Gr. kaqaro`s pure, Skr. [,c]udh to purify.]
   [1913 Webster]
   1. Pure from unlawful sexual intercourse; virtuous;
      continent. "As chaste as Diana." --Shak.
      [1913 Webster]

            Whose bed is undefiled and chaste pronounced.
                                                  --Milton.
      [1913 Webster]

   2. Pure in thought and act; innocent; free from lewdness and
      obscenity, or indecency in act or speech; modest; as, a
      chaste mind; chaste eyes.
      [1913 Webster]

   3. Pure in design and expression; correct; free from
      barbarisms or vulgarisms; refined; simple; as, a chaste
      style in composition or art.
      [1913 Webster]

            That great model of chaste, lofty, and eloquence,
            the Book of Common Prayer.            --Macaulay.
      [1913 Webster]

   4. Unmarried. [Obs.] --Chaucer.

   Syn: Undefiled; pure; virtuous; continent; immaculate;
        spotless.
        [1913 Webster]

   Chaste tree. Same as Agnus castus.
      [1913 Webster]

WordNet (r) 3.0 (2006):

chaste
    adj 1: morally pure (especially not having experienced sexual
           intercourse); "a holy woman innocent and chaste" [ant:
           unchaste]
    2: pure and simple in design or style; "a chaste border of
       conventionalized flowers"
    3: abstaining from unlawful sexual intercourse

Moby Thesaurus II by Grady Ward, 1.0:

173 Moby Thesaurus words for "chaste":
   Apostolic, Attic, Ciceronian, Encratic, Lenten, Pythagorean,
   Rechabite, Shaker, Spartan, Stoic, abase, absolute, abstemious,
   abstinent, aesthetic, afflict, artistic, ascetic, austere, bare,
   basic, becoming, beyond all praise, blotless, castigate, celibate,
   chasten, chastise, choice, classic, classical, clean, cleanly,
   clear, common, commonplace, continent, correct, decent, decorous,
   defectless, direct, discipline, easy, elegant, elementary,
   essential, ethical, everyday, excellent, faultless, finished,
   flawless, fruitarian, fundamental, garden, garden-variety, good,
   graceful, gracile, guiltless, homely, homespun, homogeneous,
   household, humble, humiliate, ideal, immaculate, impeccable,
   in good taste, indefectible, indefective, indivisible, infallible,
   innocent, irreducible, irreproachable, just right, limpid, lucid,
   maidenly, matter-of-fact, mere, modest, monolithic, moral, natural,
   neat, nephalistic, nondescript, of a piece, of choice, of quality,
   on the wagon, ordinary, peerless, pellucid, perfect, perspicuous,
   plain, pleasing, polished, primal, primary, proper, prosaic, prosy,
   pure, pure and simple, pure in heart, purehearted, quiet, refined,
   restrained, righteous, round, seemly, severe, sexually abstinent,
   sexually innocent, simon-pure, simple, single, sinless, snowy,
   spare, spotless, stainless, stark, straightforward, subdued,
   sworn off, taintless, tasteful, teetotal, terse, trim, try,
   unadorned, unadulterated, unaffected, unblemished, unblotted,
   uncluttered, uncontaminated, uncorrupt, undecorated, undefiled,
   understated, undifferenced, undifferentiated, unembellished,
   unfaultable, uniform, unlabored, unmixed, unobtrusive, unsoiled,
   unspotted, unstained, unsullied, untainted, untarnished,
   vegetarian, virgin, virginal, virtuous, well-chosen, white,
   wholesome, workaday, workday