The Collaborative International Dictionary of English v.0.48:

Pristine \Pris"tine\, a. [L. pristinus, akin to prior: cf. F.
   pristin. See Prior, a.]
   Belonging to the earliest period or state; original;
   primitive; primeval; as, the pristine state of innocence; the
   pristine manners of a people; pristine vigor.
   [1913 Webster]

WordNet (r) 3.0 (2006):

pristine
    adj 1: completely free from dirt or contamination; "pristine
           mountain snow"
    2: immaculately clean and unused; "handed her his pristine white
       handkerchief"

Moby Thesaurus II by Grady Ward, 1.0:

160 Moby Thesaurus words for "pristine":
   aboriginal, ancestral, angelic, antepatriarchal, artless,
   atavistic, autochthonous, basal, basic, blameless, bright, callow,
   central, chaste, childlike, clear, crucial, dewy, dovelike,
   earliest, elemental, elementary, embryonic, ever-new, evergreen,
   extra, faultless, first, firsthand, fledgling, fresh, fundamental,
   generative, genetic, germinal, green, guiltless, harmless,
   held back, held in reserve, held out, humanoid, immaculate,
   immature, in abeyance, in embryo, in hand, in ovo, in the clear,
   in the raw, inartificial, incorrupt, initial, innocent, intact,
   inviolate, lamblike, maiden, maidenly, mint, native, natural,
   neoteric, nestling, new, not guilty, offenseless, original,
   patriarchal, preadamite, preglacial, pregnant, prehistoric,
   prehuman, prelapsarian, primal, primary, prime, primeval,
   primitive, primogenial, primoprimitive, primordial, protogenic,
   protohistoric, protohuman, pure, put aside, put by, radical, raw,
   reproachless, reserve, rudimentary, sans reproche, saved,
   scatheless, seminal, sempervirent, sinless, spare, spotless,
   stored, suspended, to spare, unapplied, unbeaten, unbroken,
   unbruised, unconsumed, uncorrupted, undamaged, undefaced,
   undefiled, undeformed, undemolished, undestroyed, undeveloped,
   unemployed, unexercised, unexpended, unfaded, unfallen, unfledged,
   unhandled, unharmed, unhurt, unimpaired, uninjured, unlapsed,
   unmaimed, unmangled, unmarked, unmarred, unpolluted, unscarred,
   unscathed, unscratched, unshattered, unspent, unspoiled, unsullied,
   untapped, untarnished, untorn, untouched, untouched by evil,
   untried, untrodden, unused, unutilized, unwithered, unworn, vernal,
   virgin, virginal, waived, with clean hands, without reproach,
   young