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]
(..) ...it is a custom more honoured in the breach than the observance - Peace, break thee off - Look, my lord, it comes - Looks it not like the king? -Angels and ministers of grace defend us! Be thou a spirit of health or goblin damned... Bring with thee airs from heaven or blasts from hell... (..)2015 Hamlet