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

• young
• juvenile

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

There was no data on frequency, dose, or method of cannabis consumption, and only immature eggs, which are less ideal for reproduction, were available for lab experiments. —New Atlas, 10 Sep. 2025

When immature eggs—known as oocytes, which are eggs that have not yet fully developed to the stage where they can be fertilized—were exposed to THC at levels similar to those detected in patients, researchers observed more frequent chromosome errors. —Daniella Gray, MSNBC Newsweek, 9 Sep. 2025

Customer-facing systems carry the highest reputational risk when immature. —Malana Vantyler, USA Today, 9 Sep. 2025

But for now, the cost to implement what is still an unproven and immature AI solution at a small business is too prohibitive. —Gene Marks, Forbes.com, 1 Sep. 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