childish · adjective /ˈtʃɑɪl.dɪʃ/
childish (SILLY)
B2 Childish behavior is silly, like that of a small child.
Dictionary example:
Don't be so childish!
Learner example:
In comparison with other countries' tourists, they seem to be a little childish, just like a group of duckling[s] or chickens. (First Certificate in English; B2; Japanese)
childish (OF A CHILD)
B2 typical of a child
Dictionary example:
childish handwriting
Learner example:
I heard a childish voice saying to me "Take my hand." (First Certificate in English; B2; Greek)
