The state or quality of being young
boyhood, adolescence, girlhood, childhood, early manhood, early womanhood, early adulthood, puberty, tender age, juvenescence, minority, youthfulness, teen age, virginity, bloom, teens*, age of ignorance*, age of indiscretion*, awkward age*, salad days*, betweenities*.
Antonyms maturity*, old age, senility.
Young people
the younger generation, the rising generation, the next generation, juvenility, children, the young, college youth, working youth.
A young person
boy, junior, teenager, lad, youngster, stripling, minor, young man, miss, girl, maiden, fledgling, juvenile, urchin, adolescent, student, kid*, teen*, pre-teen*, gosling*, pup*, calf*; see also child.
Antonyms oldster, graybeard, dotard.