unadult

/ˌʌnəˈdʌlt/
adjective
  1. Not having the qualities or responsibilities of an adult; immature or childlike.
    • The movie had an unadult sense of humor that appealed to children.
    • She felt unadult compared to her older siblings who had jobs and families.
    • His unadult behavior at the meeting surprised his coworkers.
Antonyms
What does "unadult" mean? | whatsthatwordmean | whatsthatwordmean