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

immature talents

a vigorous but immature school of art

2

archaic : premature

immature noun

immaturely adverb

immaturity

ˌi-mə-ˈchu̇r-ə-tē 

-ˈtu̇r-, 

-ˈtyu̇r-

noun

Synonyms of immature

• 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

Too naive, too immature to understand. —Hua Hsu, New Yorker, 20 Apr. 2026

The landscaping was sparse and immature. —Literary Hub, 14 Apr. 2026

The two did a nice job portraying teenagers who go back and forth from sincere to ridiculously immature, but the best part was their horror when Jost fired back. —Omar L. Gallaga, Los Angeles Times, 12 Apr. 2026

Simandl was then rushed to Tampa General Hospital for urgent treatment and was diagnosed with acute promyelocytic leukemia (APL) — a rare and aggressive form of leukemia where immature white blood cells multiply uncontrollably, preventing the body from producing healthy blood cells. —Tereza Shkurtaj, PEOPLE, 11 Apr. 2026

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