youthful
youth.ful \'yu:th-f*l\ \-f*-le-\ aj 1: of, relating to, or appropriate to youth 2: being young and not yet mature 3: marked by or possessing youth 4: FRESH, VIGOROUS 5: having accomplished or undergone little erosion - youth.ful.ly av
Webster's English Dictionaryyouth.ful \'yu:th-f*l\ \-f*-le-\ aj 1: of, relating to, or appropriate to youth 2: being young and not yet mature 3: marked by or possessing youth 4: FRESH, VIGOROUS 5: having accomplished or undergone little erosion - youth.ful.ly av