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]
(..) Yes! They're just goddamn trees! - You need to wake up, Parker. - No. You need to wake up. The wealth of this world isn't in the ground. It's all around us. The Na'vi know that, and they are fighting to defend it. If you want to share this world with them, you need to understand them. (..)2009 Avatar