Juvenile (?; 277), a. [L. juvenilis, from juvenis young; akin to E. young: cf. F. juvénile, juvénil. See Young.]
[1913 Webster]

1. Young; youthful; as, a juvenile appearance. “A juvenile exercitation.” Glanvill.
[1913 Webster]

2. Of or pertaining to youth; as, juvenile sports.

3. Characteristic of children; immature; childish; puerile; infantile; as, a juvenile temper tantrum.
[PJC]

Syn. -- Puerile; boyish; childish. See Youthful.
[1913 Webster]