Breadcrumb Home > Thesaurus > I Synonyms of infantilism Find synonyms for: Noun 1. infantilism, abnormality, abnormalcy usage: an abnormal condition in which an older child or adult retains infantile characteristics 2. infantilism, misbehavior, misbehaviour, misdeed usage: infantile behavior in mature persons WordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved.Definition and meaning of infantilism (Dictionary) TrendingHere are the facts and trivia that people are buzzing about. Chinese New Year History, Meaning, and Celebrations Current Events This Week: February 2024 Valentine's Day Valentine's Day History Mardi Gras 30 "Charlie and the Chocolate Factory" Quotes ✖ Related Content Daily Word Quiz: irascible Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language