The Collaborative International Dictionary of English v.0.48:

Unfledged \Un*fledged"\, a.
   Not fledged; not feathered; hence, not fully developed;
   immature. --Dryden.
   [1913 Webster]

WordNet (r) 3.0 (2006):

unfledged
    adj 1: (of birds) not yet having developed feathers; "a small
           unfledged sparrow on the window sill" [syn: unfledged,
           immature] [ant: fledged, mature]
    2: (of an arrow) not equipped with feathers; "shot an unfledged
       arrow" [syn: unfledged, fledgeless, unvaned]
    3: young and inexperienced; "a fledgling enterprise"; "a
       fledgling skier"; "an unfledged lawyer" [syn: fledgling,
       unfledged, callow]

Moby Thesaurus II by Grady Ward, 1.0:

80 Moby Thesaurus words for "unfledged":
   a novice at, a stranger to, adolescent, at half cock, budding,
   callow, dewy, ever-new, evergreen, firsthand, fledgling, fresh,
   green, green as grass, growing, half-baked, half-cocked,
   half-grown, ignorant, ill-digested, immature, impubic,
   inexperienced, infant, ingenuous, innocent, intact, juicy,
   juvenile, maiden, maidenly, minor, naive, neoteric, nestling, new,
   new to, new-fledged, original, pristine, raw, ripening, sappy,
   sempervirent, tender, unaccustomed to, unacquainted with, unadult,
   unbeaten, unconversant, unconversant with, underage, underripe,
   undeveloped, unexperienced, unfamiliar with, unformed, ungrown,
   unhandled, uninitiated in, unlicked, unmatured, unmellowed,
   unpracticed, unpracticed in, unripe, unseasoned, unskilled in,
   untouched, untried, untrodden, unused, unused to, unversed,
   unversed in, vernal, virgin, virginal, young, youthful