adj. 1
Youthful; having the look or qualities of a young person.
My grandmother is a very active woman and is quite young for her age.
adj. 2
Having little experience; inexperienced; unpracticed; ignorant; weak.
adj. 3
In the early part of growth or life; born not long ago.
these picture books are for young readers
n. 1
Offspring, especially the immature offspring of animals.
The lion caught a gnu to feed its young.

Related words

Word family: youth
Phrases: young man young blood young lady young fustic young ginger young adult young boy young buck
Is a kind of: new

Forms

Young, New, Old, Modern, Ancient or Recent?

New is opposed to old, modern to ancient, recent to remote, young to old, aged, etc.

J. C. Fernald, English Synonyms and Antonyms (1914)

juvenile Recently juvenile delinquency has been on the rise.
youthful Dmitri wants to maintain his youthful appearance.
adolescent The adolescent giraffe was banished from the herd.
boyish I saw his dark face lit up with a boyish enthusiasm as he gazed about him.
inexperienced Tom is inexperienced and makes extreme statements.

Use in printed books, per decade from 1850 to 2019.

3 letters: new¹
5 letters: small¹, fresh¹, youth¹, brood¹
6 letters: little², junior², tender², boyish², vernal²
7 letters: progeny³, girlish², untried²
8 letters: innocent³, juvenile³, childish², immature³, youthful², untested³, teenaged²
9 letters: offspring², infantile³, youngling
10 letters: adolescent⁴, unseasoned
11 letters: undeveloped⁴
13 letters: inexperienced⁵
14 letters: underdeveloped⁵

The small number after each word is its number of syllables (little² = 2 syllables).