xiǎo'ér​kē

childish

小儿科 (小兒科) xiǎo'ér​kē
childish noun
acting in an immature, petty, or stingy manner

Don't be so childish; be more generous.

child's play noun
something very easy to do or of little importance; a trifle

Repairing this computer is child's play for him.

pediatrics noun
the branch of medicine dealing with children or a pediatric department

He is a doctor in the pediatrics department of the hospital.

Frequency

Movie subtitles
2.06 per million appears in 1% of films
Written text
0.858 per million

Sources

Definitions
CC-CEDICT