GRE infantile Definition Childish or immature in behavior or thinking. Example "His infantile remarks ruined the serious discussion." Sign in to save GRE PDF — $25 ← infant infantry → Related words GRE awe GRE smithereens GRE abacus SAT abase GRE abash GRE abate GRE abbreviate GRE abbreviation SAT abdicate SAT abdomen GRE abduct GRE aberrant