Immature

/ˌɪməˈtjʊr/

Meaning & Definition

adjective
Not fully developed or grown; lacking maturity.
His immature attitude toward responsibility led to many missed deadlines.
Behaving in a childish or naive manner.
She found his immature jokes quite annoying at such a serious event.
In the early stages of development or growth.
The immature plants need extra care to survive the winter.

Etymology

Late Latin 'immaturus', from 'in-' meaning 'not' + 'maturus' meaning 'ripe, mature'.

Common Phrases and Expressions

immature behavior:
Exhibiting childish or unrefined conduct.
immature attitude:
Displaying a mindset that lacks sophistication.
immature jokes:
Humor that is simplistic or appeals to a younger audience.

Related Words

Slang Meanings

Acting like a child.
Stop being so childish; you're acting immature.
Throwing a fit.
He threw a fit when things didn't go his way; so immature!