[ 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).

Origin of infantile

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

Related forms

in·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 Forms

infantility (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

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.