Definition of "young"

Bliss was it in that dawn to be alive,But to be young was very heaven!

1809 October 26, William Wordsworth, “The French Revolution as It Appeared to Enthusiasts at Its Commencement”, in Friend, No. 11, ll. 4-5

"What a charming amusement for young people this is, Mr. Darcy! There is nothing like dancing after all. I consider it as one of the first refinements of polished society."

1813, Jane Austen, Pride and Prejudice

I stumbled along through the young pines and huckleberry bushes. Pretty soon I struck into a sort of path that, I cal'lated, might lead to the road I was hunting for. It twisted and turned, and, the first thing I knew, made a sudden bend around a bunch of bayberry scrub and opened out into a big clear space like a lawn.

1913, Joseph C. Lincoln, chapter 1, in Mr. Pratt's Patients

Irregular bedtimes may disrupt healthy brain development in young children, according to a study of intelligence and sleeping habits. ¶ Going to bed at a different time each night affected girls more than boys, but both fared worse on mental tasks than children who had a set bedtime, researchers found.

2013 July 19, Ian Sample, “Irregular bedtimes may affect children's brains”, in The Guardian Weekly, volume 189, number 6, page 34

[…] while the Fears of the People were young, they were encreas’d strangely by several odd Accidents […]

1722, Daniel Defoe, A Journal of the Plague Year‎, London: E. Nutt et al, page 23

And thou, our Mother, twice two centuries young, / Bend with bright shafts of truth thy bow fresh-strung.

1906, Robertson Nicoll, Tis Forty Years Since, quoted in T. P.'s Weekly, volume 8, page 462

The young Mr. Chester must be in the wrong, and the old Mr. Chester must be in the right.

1841, The Museum of Foreign Literature, Science, and Art

[…] Miss Hessy is as pretty a girl as eye can see, in her young twenties and a bit of a fortune to boot.

1922, E. Barrington, “The Mystery of Stella” in “The Ladies!” A Shining Constellation of Wit and Beauty, Boston: Atlantic Monthly Press, pp. 40-41

Ephraim would be in his young thirties.

1965, Muriel Spark, The Mandelbaum Gate, London: Macmillan, Part One, Chapter 1

[…] while this may appeal to older, better-off shoppers, vast numbers, especially those in their teens and young twenties, still want fast, cheap fashion.

2008 January 20, Alice Fisher, “Grown-up chic is back as high street goes upmarket”, in The Guardian

Think of banking today and the image is of grey-suited men in towering skyscrapers. Its future, however, is being shaped in converted warehouses and funky offices in San Francisco, New York and London, where bright young things in jeans and T-shirts huddle around laptops, sipping lattes or munching on free food.

2013 August 3, “Revenge of the nerds”, in The Economist, volume 408, number 8847

Come, come, elder brother, you are too young in this.

c. 1598–1600 (date written), William Shakespeare, “As You Like It”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, [Act I, scene i]

There is a logic in this behavior: a mother will not come into breeding condition again unless her young is ready to be weaned or has died, so killing a baby may hasten […]

2010, Mammal Anatomy: An Illustrated Guide‎, page 21

The aging (or younging) of a population refers to the fact that a population, as a unit of observation, is getting older (or younger).

1993, Jacob S. Siegel, A Generation of Change, page 5

Medicare data was "younged" by a month to achieve conformity with the conventional completed ages recorded in the census.

1984, US Bureau of the Census, Current Population Reports‎, page 74

Shoshonitic magmatism younged southwards in the Superior Province, commensurate with the southwardly diachronous accretion of allochthonous subprovinces.

1994, R. Kerrich, D.A. Wyman, “The mesothermal gold-lamprophyre association”, in Mineralogy and Petrology

The existence of magmatic belts younging northward implies that slabs of Asian mantle subducted one after another under ranges north of the Himalayas.

2001 November 23, Paul Tapponnier et al., “Oblique Stepwise Rise and Growth of the Tibet Plateau”, in Science‎, volume 294, number 5547, pages 1671–1677