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

He’s been there; Harper was emotional — at times, immature — as a younger player. —Matt Gelb, The Athletic, 25 Mar. 2025

From its opening scenes, Severance has presented the procedure the show is named for as a kind of birth, the spawning of a new, immature being. —Sophie Gilbert, The Atlantic, 21 Mar. 2025

Jamie’s conflicting reality is truly ominous: the immature boy, the furious man, and the jagged cusp between both. —Raven Smith, Vogue, 19 Mar. 2025

Thursday, the Santa Clara County Vector Control District plans to use a helicopter to treat the area with naturally occurring microbes and a hormone regulator that prevents immature winter salt marsh mosquitoes from developing into adults. —Jason Green, The Mercury News, 19 Mar. 2025

Word History

Etymology

Latin immaturus, from in- + maturus mature

First Known Use

1548, in the meaning defined at sense 2

Rhymes for immature

• annexure
• embouchure
• epicure
• paramour
• premature
• reassure
• reinsure
• sinecure
• abjure
• adjure
• allure
• assure

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