infantile

adjectives

indicating a lack of maturity
"childish tantrums"; "infantile behavior"
childish, infantile
of or relating to infants or infancy
"infantile paralysis"
infantile
pertains to
infancy
being or befitting or characteristic of an infant
"infantile games"
infantile
is similar to
(used of living things especially persons) in an early period of life or development or growth
"young people"
immature, young