Infantile means having or showing the qualities associated with infants or young children. It can also refer to behavior that is childish or immature.


US English

UK English

Part of Speech



childlike, immature, juvenile, babyish, childish, puerile, silly, frivolous, naive.


Adult, mature, sophisticated, responsible, serious, sensible, wise, grown-up.

Word Forms

Part of Speech Words
Noun infancy, infants, infant, infancies
Verb None
Adjective infantile
Adverb None

Example Sentences

  • His constant tantrums and defiance of authority are characteristic of infantile behavior.

  • The comedian’s humor was criticized for being infantile and lacking sophistication.

  • We must abandon our infantile fears and confront the challenges of life with courage and maturity.

  • Her interests in fairy tales and cartoon characters suggest a somewhat infantile taste in entertainment.


Infantile is an adjective that describes behavior or qualities that are typically associated with infants or young children. It is often used to describe a person or their actions as being childish, immature or foolish. The word is derived from the Latin word “infantilis,” which means “of an infant.”

Infantile is a simple word that is easily understood by most English speakers, and it is often used in a wide range of contexts. For example, parents may use this word to describe their children’s behavior when they are acting out or misbehaving. It can also be used to describe the behavior of adults who are acting in an immature or irresponsible manner.

The word infantile can be modified with various prefixes or suffixes to create related words. For example, the prefix “pre-” can be added to create the word “preinfantile,” which means “relating to a period before infancy.” The suffix “-ism” can be added to create “infantilism,” which is a medical condition characterized by the persistence of infantile behaviors or attitudes.

Overall, the word infantile is a useful word for describing behavior that is characterized by immaturity or childishness. It is a fairly common word that is easily understood by most English speakers, and it can be used in a variety of different contexts.