The Collaborative International Dictionary of English v.0.48:

Unspent \Unspent\
   See spent.

WordNet (r) 3.0 (2006):

unspent
    adj 1: (of financial resources) not spent; "unexpended funds";
           "his unspent allowance" [syn: unspent, unexpended]

Moby Thesaurus II by Grady Ward, 1.0:

32 Moby Thesaurus words for "unspent":
   extra, fresh, held back, held in reserve, held out, in abeyance,
   in hand, mint, new, original, pristine, put aside, put by, reserve,
   saved, spare, stored, suspended, to spare, unapplied, unbeaten,
   unconsumed, unemployed, unexercised, unexpended, unhandled,
   untapped, untouched, untrodden, unused, unutilized, waived