infantile

adjective

in·​fan·​tile ˈin-fən-ˌtī(-ə)l  -tᵊl  -ˌtēl  -(ˌ)til 

1

: of or relating to infants or infancy

2

: suitable to or characteristic of an infant

especially : very immature

infantile humor

infantility

ˌin-fən-ˈti-lə-tē 

noun

Synonyms

• adolescent
• babyish
• childish
• immature
• jejune
• juvenile
• kiddish
• puerile

Examples of infantile in a Sentence

the infantile humor that teenage boys are justly famous for

Recent Examples on the Web

The curious case of infantile amnesia The phenomenon of not remembering anything from early childhood is known as infantile amnesia. —Aamir Khollam, Interesting Engineering, 21 Mar. 2025

If nothing else is done with those mice, that association will apparently be forgotten later in life due to infantile amnesia. —John Timmer, Ars Technica, 21 Mar. 2025

For a long time, infantile amnesia was thought to be tied to an inability to make memories in infancy. —Sam Walters, Discover Magazine, 20 Mar. 2025

If this is correct, is there a connection between song and the most basic infantile communication? —Aaron Shattuck, Scientific American, 18 Feb. 2025

Word History

First Known Use

1696, in the meaning defined at sense 1

Phrases Containing infantile

• infantile paralysis

Kids Definition

infantile

adjective

in·​fan·​tile ˈin-fən-ˌtīl 

-tᵊl,

-ˌtēl

: of, relating to, or resembling infants or infancy

also : childish

Medical Definition

infantile

adjective

in·​fan·​tile ˈin-fən-ˌtīl  -tᵊl  -ˌtēl  -(ˌ)til 

1

: of, relating to, or occurring in infants or infancy

infantile eczema

2

: suitable to or characteristic of an infant

especially : very immature