The team is looking to 'defend' its national title. [=to win the national title again]
As a U.S. senator, it is my responsibility to 'defend' [='uphold'] the Constitution.
She successfully 'defended' her championship. [=she won the championship again]
(..) We got Senators jumping out of our asses And the director is very concerned. They will not stop until they have a body. I ran it. I'll defend it. Done. I tell you what, man, it's good to be back in Kuwait. It's good to see you again. Huh? It's been a while. (..)2012 Zero Dark Thirty