immature

Definitions

Not fully developed or grown; not yet mature.

Having or showing an emotional or intellectual development appropriate to a younger person.

Examples

It was very immature of him to make fun of his classmate's presentation.

The young puppy displayed immature behavior by chewing on the expensive leather shoes.

Synonyms

childish juvenile infantile puerile unripe callow undeveloped

Antonyms

mature adult grown-up sophisticated experienced developed ripe