immature
adj.adj. behaving in a way that is much younger than your actual age. You use this to describe someone who is not yet emotionally or mentally developed.
adj. displaying emotional or cognitive development below what is expected for a person's chronological age. Often carries a pejorative nuance when applied to adults.
His immature behavior at the party embarrassed his friends.
The manager's immature reaction to criticism made it difficult for the team to provide honest feedback.
While the biological markers of adulthood are clear, many psychologists argue that modern social structures allow individuals to remain emotionally immature well into their late twenties.
From Middle French immature. Partially displaced unripe, from Old English unrīpe (“unripe, immature”).
Typically used as a gradable adjective; often follows linking verbs like 'be', 'seem', or 'act'.
He is very unmature.He is very immature.The correct negative prefix for 'mature' is 'im-', not 'un-'.