Sentence:  Of the two , Porter is justly the better known , for he went far beyond the vital finding of fiction for films to take the first step toward fashioning a language of film , toward making the <WSD>motion</WSD> picture the intricate , efficient time machine that it has remained since , even in the most inept hands . 
Meaning of the word marked with <WSD> tags:  a form of entertainment that enacts a story by sound and a sequence of images giving the illusion of continuous movement