# infantile

/ˈɪnfəntɪɫ/ (US) · /ˈɪnfəntˌaɪl/ (UK) · CEFR C1 · Adjective

Source: https://englishreference.com/word/infantile
Updated: 2026-05-20

## Definition

behaving in a way that is childish or not mature. You use this to describe someone who acts like a small child, often in a way that is annoying or silly.

For teachers: characterised by or suitable for an infant; lacking maturity or sophistication. Often used to describe behavior that is perceived as childish or inappropriate for an adult.

## Examples

- His infantile behavior made it difficult for him to work with others.
- The manager was frustrated by the infantile arguments between the two junior staff members over a minor mistake.
- The critic argued that the film's infantile plot was a deliberate attempt to appeal to a younger demographic, though it failed to resonate with older viewers.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.