The Collaborative International Dictionary of English v.0.48:

Reluctant \Re*luc"tant\ (-tant), a. [L. reluctans, -antis, p.
   pr. of reluctari. See Reluct.]
   1. Striving against; opposed in desire; unwilling;
      disinclined; loth.
      [1913 Webster]

            Reluctant, but in vain.               --Milton.
      [1913 Webster]

            Reluctant now I touched the trembling string.
                                                  --Tickell.
      [1913 Webster]

   2. Proceeding from an unwilling mind; granted with
      reluctance; as, reluctant obedience. --Mitford.
      [1913 Webster]

   Syn: Averse; unwilling; loth; disinclined; repugnant;
        backward; coy. See Averse.
        [1913 Webster]

WordNet (r) 3.0 (2006):

reluctant
    adj 1: unwillingness to do something contrary to your custom; "a
           reluctant smile"; "loath to admit a mistake" [syn:
           loath, loth, reluctant]
    2: disinclined to become involved; "they were usually reluctant
       to socialize"; "reluctant to help"
    3: not eager; "foreigners stubbornly reluctant to accept our
       ways"; "fresh from college and reluctant for the moment to
       marry him"

Moby Thesaurus II by Grady Ward, 1.0:

116 Moby Thesaurus words for "reluctant":
   afraid, ambling, antagonistic, apathetic, averse, backward,
   balking, balky, calculating, careful, cautious, chary, circumspect,
   claudicant, complaining, crawling, creeping, creeping like snail,
   deliberate, dilatory, disinclined, disputatious, disputing,
   dissentient, dissenting, easy, faltering, flagging, foot-dragging,
   fractious, gentle, gradual, grudging, halting, hesitant, hobbled,
   hobbling, idle, indifferent, indisposed, indolent, laggard,
   languid, languorous, lazy, leery, leisurely, limping, loath,
   lumbering, moderate, noncooperative, objecting, obstructive,
   on the barricades, opposed, perfunctory, poking, poky,
   proof against, protesting, rebellious, recalcitrant, refractory,
   relaxed, renitent, repellent, resistant, resisting, resistive,
   restive, retardant, retardative, sauntering, shuffling, shy, slack,
   slothful, slow, slow as death, slow as molasses, slow as slow,
   slow to, slow-crawling, slow-foot, slow-going, slow-legged,
   slow-moving, slow-paced, slow-poky, slow-running, slow-sailing,
   slow-stepped, sluggish, snail-paced, snaillike, staggering,
   strolling, tentative, toddling, tortoiselike, tottering, trudging,
   turtlelike, uncooperative, uneager, unenthusiastic, unhurried,
   unsubmissive, unwilling, unyielding, unzealous, up in arms,
   waddling, wary, withstanding