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

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

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