adjective
- of, like, or befitting a child: childish games.
- puerile; weak; silly: childish fears.
adjective
- in the manner of, belonging to, or suitable to a child
- foolish or petty; puerilechildish fears
Old English cildisc “proper to a child;” see child + -ish. Meaning “puerile, immature, like a child” in a bad sense is from early 15c. Related: Childishly; childishness.