immature

adjective

im·​ma·​ture ˌi-mə-ˈchu̇r  -ˈtu̇r 

-ˈtyu̇r

1

a

: exhibiting less than an expected degree of maturity

emotionally immature adults

b

: lacking complete growth, differentiation, or development

immature fruits

a sexually immature bird

c

: having the potential capacity to attain a definitive form or state : crude, unfinished

a vigorous but immature school of art

2

archaic : premature

immature noun

immaturely adverb

immaturity

ˌi-mə-ˈchu̇r-ə-tē 

-ˈtu̇r-

-ˈtyu̇r-

noun

Synonyms

• adolescent
• juvenile
• young
• youngish
• youthful

Examples of immature in a Sentence

The flock included both adult and immature birds.

His teachers have complained about his immature behavior.

Recent Examples on the Web

These clowns dressed as presidents appear immature and narcissistic. —Nancy Tartaglione, Deadline, 9 Feb. 2025

A lot of us automatically use certain emotionally immature phrases without even thinking about it. —Kathy and Ross Petras, Contributors, CNBC, 1 Feb. 2025

Harvesting immature follicles requires only one or two days of hormonal injections, or skips the process altogether. —Kristen V. Brown, The Atlantic, 27 Jan. 2025

Mikey Madison shines as the title character, a dancer who ends up the wife of an immature, wealthy, young Russian guy who didn’t ask his crime lord daddy for permission to get married. —Brian Tallerico, Vulture, 17 Dec. 2024

Word History

Etymology

Latin immaturus, from in- + maturus mature

First Known Use

1548, in the meaning defined at sense 2

Kids Definition

immature

adjective

im·​ma·​ture ˌim-ə-ˈt(y)u̇(ə)r 

1

: not mature or fully developed : young, unripe

an immature bird

immature fruit

2

: showing less than an expected degree of maturity

immature behavior

immaturely adverb

Medical Definition

immature

adjective

im·​ma·​ture

ˌim-ə-ˈt(y)u̇(ə)r also -ˈchu̇(ə)r

: lacking complete growth, differentiation, or development

immature blood cells

emotionally immature

immaturely adverb

immaturity

-ˈt(y)u̇r-ət-ē also -ˈchu̇r-

noun

plural immaturities