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]
(..) He was protecting me! He's not dangerous. They've killed hundreds of us! And we've killed thousands of them! They defend themselves, that's all! They raid us because they have to. If they don't bring enough food back, they'll be eaten themselves. There's something else (..)2010 How to Train Your Dragon