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

By the way, Key limes are green when immature and yellow when ripe, further adding to the color confusion. —Chadd Scott, Southern Living, 29 Dec. 2024

Kids who are young for their grade are, almost by definition, more immature than their peers. —Greg Rosalsky, NPR, 17 Dec. 2024

Develop a robust risk management strategy to address potential challenges, such as immature technology, data and application security, scaling issues, and regulatory compliance. —Sanjay Srivastava, Forbes, 12 Dec. 2024

Because of their immature immune systems, infants younger than 1 year old are at highest risk of contracting whooping cough -- also known as pertussis -- and are at most significant risk of severe illness. —Sabrina Malhi The Washington Post, arkansasonline.com, 26 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