infantile

American  

[in-fuhn-tahyl, -til] / ˈɪn fənˌtaɪl, -tɪl /

adjective

1. characteristic of or befitting an infant; babyish; childish.

   infantile behavior.

   Synonyms:

   weak, immature, puerile

   Antonyms:

   mature, adult

2. of or relating to infants or infancy.

   infantile diseases.

3. Physical Geography. youthful.

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infantile British  

/ ˈɪnfənˌtaɪl, ˌɪnfənˈtɪlɪtɪ /

adjective

1. like a child in action or behaviour; childishly immature; puerile

2. of, relating to, or characteristic of infants or infancy

3. in an early stage of development

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Related Words

See childish.

Other Word Forms

• infantility noun

Etymology

Origin of infantile

From the Latin word infantīlis, dating back to 1690–1700. See infant, -ile

Example Sentences

And don’t get me started on the endless, infantile standing ovations.

From MarketWatch

“Colin is deeply romantic and has a sort of slightly infantile version of romance,” Lighton said of the character the story unfolds through.

From The Wall Street Journal

They might also have had an infantile sense of humor.

From The Wall Street Journal

Emojis can have an "infantile connotation" which could lead to people perceiving you as younger, less senior, capable or responsible, he says.

From BBC

“There was a lo-fi quality about it. It had something candid that didn’t necessarily have an infantile tone but had a lightness. And we could add lyrics to that music.”

From Los Angeles Times

Related Words

• childish
• sophomoric