Sentence:  [O]ne of Gore's senior advisers, top-tier lobbyist Peter Knight, is a <WSD>hired gun</WSD> for pharmaceuticals giant Schering-Plough. 
Meaning of the word marked with <WSD> tags:  A person who is employed to advance the interests of his or her employer, especially in a vigorous manner using such methods as political lobbying, legal advocacy, or persuasion.