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


characteristic of or befitting an infant; babyish; childish: infantile behavior.
of or relating to infants or infancy: infantile diseases.
Physical Geography. youthful(def 5).

Nearby words

  1. infant prodigy,
  2. infant school,
  3. infanta,
  4. infante,
  5. infanticide,
  6. infantile acropustulosis,
  7. infantile autism,
  8. infantile cortical hyperostosis,
  9. infantile digital fibromatosis,
  10. infantile eczema

Origin of infantile

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

Related formsin·fan·til·i·ty [in-fuhn-til-i-tee] /ˌɪn fənˈtɪl ɪ ti/, noun

Synonym study

1. See childish. Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for infantile

British Dictionary definitions for infantile


/ (ˈɪnfənˌtaɪl) /


like a child in action or behaviour; childishly immature; puerile
of, relating to, or characteristic of infants or infancy
in an early stage of development
Derived Formsinfantility (ˌɪnfənˈtɪlɪtɪ), noun

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for infantile



mid-15c., "pertaining to infants," from Latin infantilis "pertaining to an infant," from infans (see infant). Sense of "infant-like" is from 1772.

Online Etymology Dictionary, © 2010 Douglas Harper

Medicine definitions for infantile


[ ĭnfən-tīl′, -tĭl ]


Of or relating to infants or infancy.
Displaying or suggesting a lack of maturity; extremely childish.

The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.