Sentence:  I mean something more like Freud 's concept of the utility of `` play '' to a small child : he plays `` house '' or `` doctor '' or `` fireman '' as a way of <WSD>mastering</WSD> slightly frightening experiences , reliving them imaginatively until they are under control . 
Meaning of the word marked with <WSD> tags:  get on top of; deal with successfully