a bit previous, adolescent, advanced, amateur, amateurish, arrested, at half cock, babbling, backward, blithering, burbling, callow, crackbrained, cracked, crazy, cretinistic, cretinous, dabbling, dilettante, dilettantish, dithering, driveling, drooling, far ahead, fledgling, forward, green, half-assed, half-cocked, half-grown, half-witted, hasty, idiotic, ill-considered, ill-digested, imbecile, imbecilic, immature, impubic, impulsive, juvenile, maundering, mentally defective, mentally deficient, mentally handicapped, mentally retarded, mongoloid, moronic, not all there, not firm, overhasty, oversoon, precipitate, precocious, premature, previous, raw, retarded, rushed, sciolistic, shallow, simple, simpleminded, simpletonian, slobbering, smattering, sophomoric, subnormal, superficial, too early, too soon, uncrystallized, underripe, unfledged, ungrown, unjelled, unmatured, unmeditated, unmellowed, unpremeditated, unprepared, unripe, unseasoned, untimely