Immature

1. (a.) Not full-grown; unripe; unfinished; as, immature fruit; immature character; immature plans.

2. (a.) Premature; untimely; too early; as, an immature death.

Thesaurus Entries

a novice at, a stranger to, adolescent, adulterated, amateur, amateurish, arrested, at half cock, babish, babyish, blemished, budding, callow, childish, childlike, dabbling, damaged, defective, deficient, dewy, dilettante, dilettantish, embryonic, erroneous, ever-new, evergreen, failing, fallible, faulty, firsthand, fledgling, found wanting, fresh, green, green as grass, growing, half-assed, half-baked, half-cocked, half-grown, hypoplastic, ignorant, ill-digested, impaired, imperfect, imprecise, impubic, impure, in arrear, in arrears, in default, in short supply, inaccurate, inadequate, incomplete, inexact, inexperienced, infant, infantile, infantine, ingenuous, innocent, intact, jejune, juicy, juvenile, lacking, maiden, maidenly, makeshift, mediocre, minor, missing, mixed, naive, needing, neoteric, nestling, new, new to, new-fledged, not perfect, off, original, part, partial, patchy, precocious, premature, pristine, puerile, raw, ripening, rudimentary, sappy, scant, scanty, sciolistic, scrappy, sempervirent, shallow, short, shy, sketchy, smattering, sophomoric, superficial, tender, unaccustomed to, unacquainted with, unadult, unbeaten, unconversant, unconversant with, underage, underdeveloped, underripe, undeveloped, uneven, unexperienced, unfamiliar with, unfinished, unfledged, unformed, ungrown, unhandled, uninitiated in, unlicked, unmatured, unmellowed, unperfected, unpracticed, unpracticed in, unripe, unseasoned, unskilled in, unsophisticated, unsound, unthorough, untouched, untried, untrodden, unused, unused to, unversed, unversed in, vernal, virgin, virginal, wanting, young, youthful