Sentence:  Prokofieff might well emerge as a cultural hero , who , by the force of his creative life , helped preserve the main stream of tradition , to which the surviving idioms of current experimentalism may be eventually <WSD>added</WSD> and integrated . 
Meaning of the word marked with <WSD> tags:  make an addition (to); join or combine or unite with others; increase the quality, quantity, size or scope of