childish

/ˈtʃaɪldɪʃ/
adjective
  1. Behaving in a silly or immature way, like a child.
    • Stop being so childish and accept that you can't always get what you want.
    • The manager criticized the team's childish behavior during the meeting.
    • His childish tantrum over losing the game embarrassed everyone.
  2. Typical of or suitable for a child; simple or innocent.
    • The room was decorated with childish drawings and bright colors.
    • She still has a childish love for cartoons and fairy tales.
    • His childish excitement at seeing the fireworks was contagious.
Antonyms
What does "childish" mean? | whatsthatwordmean | whatsthatwordmean