I. ˈjüvəˌnīl, -_n ə l sometimes -(ˌ)nil adjective
Etymology: French or Latin; French juvénile, from Latin juvenilis, from juvenis young person (from juvenis young) + -ilis -ile — more at young
1.
a. : of, relating to, or being a juvenile : physiologically immature or undeveloped : young
the baby snake varies in color and markings from the juvenile — Farmer's Weekly (South Africa)
his appearance was juvenile — Elinor Wylie
a juvenile period that is essentially asexual — W.C.Allee
gave her a most juvenile and engaging look — Edna Ferber
ten juvenile years of my life — F.N.Souza
b. : being or remaining in a youthful stage of development ; specifically : being a plant in which the leaves are assumed to be similar to ancestral adult forms
c. : magmatic
juvenile waters
2.
a. : of, relating to, characteristic of, or suitable for children or young people
a juvenile book
a juvenile phase of love not yet warmed into passion — C.W.Cunnington
a juvenile membership of 82,111 — C.W.Ferguson
b. : being or relating to an actor who plays a youthful part
played the juvenile lead in a new hit
3. : reflecting psychological or intellectual immaturity : unworthy of an adult : childish
the juvenile customs of fraternities — Harold Taylor
regarded their desperate rebellion as juvenile melodrama — Paul Blanshard
juvenile behavior
Synonyms: see youthful
II. noun
( -s )
1.
a. : a young person : child , youth
observed some of the evil effects of factory labor upon juveniles — Paul Woodring
leader of a gang of juveniles who stole a car recently — Springfield (Massachusetts) Daily News
b. : a book for children or young people
a general trade book as well as a juvenile — Publishers' Weekly
2.
a. : a young individual fundamentally like an adult of its kind except in size and reproductive activity
b. : a bird in juvenal plumage
c. : a 2-year old racehorse
3. : an actor who plays youthful parts ; sometimes : an actress who plays such parts