The Collaborative International Dictionary of English v.0.48:

Pansy \Pan"sy\, n.; pl. Pansies. [F. Pens['e]e thought, pansy,
   fr. penser to think, L. pensare to weigh, ponder. See
   Pensive.] (Bot.)
   A plant of the genus Viola (Viola tricolor) and its
   blossom, originally purple and yellow. Cultivated varieties
   have very large flowers of a great diversity of colors.
   Called also heart's-ease, love-in-idleness, and many
   other quaint names.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Heart's-ease \Heart's"-ease`\ (h[aum]rts"[=e]z`), n.
   1. Ease of heart; peace or tranquillity of mind or feeling.
      --Shak.
      [1913 Webster]

   2. (Bot.) A species of violet (Viola tricolor), a common
      and long cultivated European herb from which most common
      garden pansies are derived; -- called also pansy.
      [WordNet sense 1]

   Syn: wild pansy, Johnny-jump-up, heartsease,
        love-in-idleness, pink of my John, Viola tricolor.
        [1913 Webster + WordNet 1.5]

   3. (Bot.) A violet of the Pacific coast of North America
      (Viola ocellata) having white petals tinged with yellow
      and deep violet. [WordNet sense 2]

   Syn: two-eyed violet, heartsease, Viola ocellata.
        [WordNet 1.5]

   4. (Bot.) A common Old World viola (Viola arvensis) with
      creamy often violet-tinged flowers. [WordNet sense 3]

   Syn: field pansy, heartsease, Viola arvensis.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

pansy
    n 1: large-flowered garden plant derived chiefly from the wild
         pansy of Europe and having velvety petals of various colors
         [syn: pansy, Viola tricolor hortensis]
    2: a timid man or boy considered childish or unassertive [syn:
       sissy, pantywaist, pansy, milksop, Milquetoast]
    3: offensive term for an openly homosexual man [syn: fagot,
       faggot, fag, fairy, nance, pansy, queen, queer,
       poof, poove, pouf]

Moby Thesaurus II by Grady Ward, 1.0:

54 Moby Thesaurus words for "pansy":
   Milquetoast, auntie, baby, bi-guy, big baby, bisexual, bull dyke,
   butch, catamite, chicken, crybaby, doormat, dull tool, dyke, fag,
   faggot, fairy, femme, flit, fricatrice, fruit, gunsel,
   gutless wonder, homo, homophile, homosexual, homosexualist, invert,
   invertebrate, jellyfish, lesbian, lightweight, meek soul, milksop,
   mollycoddle, namby-pamby, nance, nebbish, nonentity, pantywaist,
   pathic, punk, pushover, queen, queer, sad sack, sapphist, sissy,
   softling, softy, sop, tribade, weak sister, weakling