Sentence:  I have just asked these questions in the Pentagon , in the White House , in offices of key scientists across the country and aboard the submarines that <WSD>prowl</WSD> for months underwater , with neat rows of green launch tubes which contain Polaris missiles and which are affectionately known as `` Sherwood Forest '' . 
Meaning of the word marked with <WSD> tags:  move about in or as if in a predatory manner