infantile

Of or relating to infants or infancy.

Displaying or suggesting a lack of maturity; childish: synonym: young.

In geology, of a land form, having been subjected to the processes of erosion, in its present relation to base-level, for a very short lime.

Of or belonging to infants or little children; pertaining to or characteristic of infancy or an infant.

Of the character of an infant; infant-like.