1. the quality or state of being juvenile; youthfulness
2. childish or immature behavior

Examples

• The juvenility of his response surprised everyone at the meeting.
• Her juvenility was evident in the way she giggled at everything.
• The teacher was concerned about the student’s continued juvenility.
• Despite his age, there was a certain juvenility in his enthusiasm.
• The juvenility of the prank made it clear who was responsible.
• She tried to hide her juvenility by speaking in a deeper voice.