"infantile" in the adjective sense
1. childish, infantile
indicating a lack of maturity
"childish tantrums"
"infantile behavior"
2. infantile
of or relating to infants or infancy
"infantile paralysis"
3. infantile
being or befitting or characteristic of an infant
"infantile games"
Source: WordNet® (An amazing lexical database of English)
Princeton University "About WordNet®."
WordNet®. Princeton University. 2010.
View WordNet® License