The Collaborative International Dictionary of English v.0.48:

fundamentalist \fundamentalist\ fundamentalistic
\fundamentalistic\adj.
   1. of or pertaining to fundamentalists or fundamentalism.
      [WordNet 1.5]

   2. characteristic of a fundamentalist; -- especially,
      resembling the behavior of a fundamentalist; as, a
      fundamentalist dislike of new ideas.
      [PJC]

The Collaborative International Dictionary of English v.0.48:

fundamentalist \fundamentalist\ n.
   a supporter of fundamentalism.
   [WordNet 1.5]

WordNet (r) 3.0 (2006):

fundamentalist
    adj 1: of or relating to or tending toward fundamentalism [syn:
           fundamentalist, fundamentalistic]
    n 1: a supporter of fundamentalism

Moby Thesaurus II by Grady Ward, 1.0:

65 Moby Thesaurus words for "fundamentalist":
   Orthodox Jew, Sabbatarian, Sunni Muslim, bigoted, bitter-ender,
   canonist, conservative, creedbound, dogmatic, dour, evangelical,
   firm, hard, hidebound, hyperorthodox, impliable, inexorable,
   inflexible, iron, ironbound, ironclad, ironhanded, literalist,
   literalistic, muscle-bound, obdurate, obstinate, old liner,
   orthodox, orthodox Christian, orthodoxist, precisianist,
   precisianistic, procrustean, purist, puristic, puritan, puritanic,
   puritanical, relentless, right, right-winger, rightist, rigid,
   rigorist, rigoristic, rigorous, rockbound, standpat, standpatter,
   staunch, stiff, straightlaced, straitlaced, strict, stubborn,
   textualist, textuary, the orthodox, tory, true believer, unbending,
   uncompromising, unrelenting, unyielding