The Collaborative International Dictionary of English v.0.48:

Intransigent \In*trans"i*gent\, a. [F. intransigeant (cf. Sp.
   intransigente); pref. in- not + L. transigere to come to an
   agreement; trans across + agere to lead, act.]
   Refusing compromise; uncompromising; inflexible;
   irreconcilable. --Lond. Sat. Rev.
   [1913 Webster]

WordNet (r) 3.0 (2006):

intransigent
    adj 1: impervious to pleas, persuasion, requests, reason; "he is
           adamant in his refusal to change his mind"; "Cynthia was
           inexorable; she would have none of him"- W.Churchill; "an
           intransigent conservative opposed to every liberal
           tendency" [syn: adamant, adamantine, inexorable,
           intransigent]

Moby Thesaurus II by Grady Ward, 1.0:

74 Moby Thesaurus words for "intransigent":
   adamant, adamantine, ass, bigot, bitter-ender, brawler, bullethead,
   cast-iron, defendant, diehard, disputant, dissentient, dissident,
   dogmatist, donkey, dour, fanatic, firm, flinty, grim, hard,
   hard-core, hardnose, immovable, immutable, implacable, impliable,
   inelastic, inexorable, inflexible, intransigeant, iron,
   irreconcilable, last-ditcher, litigant, maverick, mule, naysayer,
   negativist, noncooperator, objector, obstructionist, obstructive,
   opposer, oppositionist, perverse fool, pighead, plaintiff,
   positivist, protester, purist, quarreler, relentless, resister,
   rigid, rigorous, rock-ribbed, scrapper, standpat, standpatter,
   steely, stern, stickler, stiff, unaffected, unalterable, unbending,
   unchangeable, uncompromising, ungiving, unmoved, unrelenting,
   unyielding, wrangler