noun · acting in an immature, petty, or stingy manner

别那么小儿科，大方一点吧。

noun, verb · something very easy to do or of little importance; a trifle

修理这台电脑对他来说简直是小儿科。

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

他在医院的小儿科当医生。