Sentence:  Now a quiet-spoken , middle-aged man , Fiedler is an aeronautical engineer for Lockheed 's Missiles and Space Division at Sunnyvale , where he <WSD>played</WSD> a key role in the development of the Navy 's Polaris missile . 
Meaning of the word marked with <WSD> tags:  act or have an effect in a specified way or with a specific effect or outcome