The Collaborative International Dictionary of English v.0.48:

Inexperienced \In`ex*pe"ri*enced\, a.
   Not having experience; unskilled; naive. "Inexperienced
   youth." --Cowper.
   [1913 Webster]

WordNet (r) 3.0 (2006):

inexperienced
    adj 1: lacking practical experience or training [syn:
           inexperienced, inexperient] [ant: experienced,
           experient]

Moby Thesaurus II by Grady Ward, 1.0:

106 Moby Thesaurus words for "inexperienced":
   a novice at, a stranger to, artless, awkward, befoolable,
   blankminded, born yesterday, budding, callow, dewy, disaccustomed,
   dumb, empty, empty-headed, foolable, fresh, gauche, green,
   green as grass, groping, growing, gullible, ignorant, immature,
   impubic, inane, indefensible, inept, inexpert, inexpiable,
   ingenuous, innocent, intact, juicy, know-nothing, minor, naive,
   nescient, new to, new-fledged, prentice, raw, ripening, rude,
   rusty, sappy, simple, strange to, tender, tentative, unaccustomed,
   unaccustomed to, unacquainted, unacquainted with, unadult,
   unapprized, uncomprehending, unconversant, unconversant with,
   underage, undeveloped, unenlightened, unexperienced, unfamiliar,
   unfamiliar with, unfledged, unforgivable, unformed, unhabituated,
   unhardened, unilluminated, uninformed, uninitiated, uninitiated in,
   unintelligent, uninured, unjustifiable, unknowing, unlicked,
   unmatured, unmellowed, unpardonable, unposted, unpracticed,
   unpracticed in, unripe, unschooled, unseasoned, unskilled,
   unskilled in, unsophisticated, unsure, untenable, untrained,
   untried, unused, unused to, unversed, unversed in, unwonted,
   unworldly, vacuous, vernal, virginal, weaned, young