The Collaborative International Dictionary of English v.0.48:

Unused \Un*used"\, a.
   1. Not used; as, an unused book; an unused apartment.
      [1913 Webster]

   2. Not habituated; unaccustomed.
      [1913 Webster]

            Unused to bend, impatient of control. --Thomson.
      [1913 Webster]

WordNet (r) 3.0 (2006):

unused
    adj 1: not yet used or soiled; "a fresh shirt"; "a fresh sheet
           of paper"; "an unused envelope" [syn: fresh, unused]
    2: not yet put into use; "we bought an unused car for a change"
    3: not in active use; "the machinery sat idle during the
       strike"; "idle hands" [syn: idle, unused]
    4: infrequently exposed to; "feet unused to shoes"

Moby Thesaurus II by Grady Ward, 1.0:

97 Moby Thesaurus words for "unused":
   a stranger to, abandoned, as a bonus, callow, derelict, dewy,
   disaccustomed, disused, ever-new, evergreen, extra, firsthand,
   fledgling, for lagniappe, fresh, given up, green, held back,
   held in reserve, held out, idle, ignorant, immature, in abeyance,
   in hand, inexperienced, intact, left, leftover, maiden, maidenly,
   mint, neglected, neoteric, nestling, net, new, new to, odd,
   original, outstanding, over, over and above, overplus, pristine,
   put aside, put by, raw, remaining, remanent, reserve, rusty, saved,
   sempervirent, spare, stored, superfluous, supernumerary, surplus,
   surviving, suspended, to spare, unaccustomed, unaccustomed to,
   unacquainted with, unapplied, unbeaten, unconsumed,
   unconversant with, undeveloped, unemployed, unexercised,
   unexpended, unfamiliar with, unfledged, unhabituated, unhandled,
   unhardened, uninitiated in, uninured, unpracticed, unseasoned,
   unspent, untapped, untouched, untrained, untried, untrodden,
   unused to, unutilized, unwonted, vernal, virgin, virginal, waived,
   weaned, young