The Collaborative International Dictionary of English v.0.48:

butch \butch\ (b[.u]ch), adj.
   1. markedly masculine in appearance or manner; -- used of
      men.

   Syn: macho.
        [WordNet 1.5]

   2. same as lesbian. [pejorative]
      [WordNet 1.5]

The Collaborative International Dictionary of English v.0.48:

butch \butch\ n.
   a lesbian who is noticeably masculine.

   Syn: dyke.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

butch
    adj 1: used of men; markedly masculine in appearance or manner
           [syn: butch, macho]
    2: (of male or female homosexuals) characterized by
       stereotypically male traits or appearance
    n 1: (slang) offensive term for a lesbian who is noticeably
         masculine [syn: butch, dike, dyke]

Moby Thesaurus II by Grady Ward, 1.0:

48 Moby Thesaurus words for "butch":
   AC-DC, amazon, amphierotic, androgyne, auntie, autoerotic, bi-guy,
   bisexed, bisexual, bull dyke, catamite, chicken, deviant, dyke,
   effeminate, fag, faggot, fairy, femme, flit, fricatrice, fruit,
   gay, gunsel, homo, homoerotic, homophile, homosexual,
   homosexualist, hoyden, invert, lesbian, mannish, nance, pansy,
   pathic, perverted, punk, queen, queer, romp, sapphic, sapphist,
   tomboy, transvestite, tribade, tribadistic, virago