/ˈjo͞ovəˌnīl/ /-vənl/
Adjective
1. Young; not fully developed (wiktionary.org)
2. Characteristic of youth or immaturity; childish (wiktionary.org)
Noun, pl. juveniles
1. A prepubescent child. (wiktionary.org)
2. A person not legally of age, or who is younger than may be charged with an offence. (wiktionary.org)
3. An animal that is not sexually mature. (wiktionary.org)
4. An actor playing a child’s role. (wiktionary.org)
Word origin: From Latin iuvenilis “of or belonging to youth,” from iuvenis “young person,” originally “young”