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]
(..) I, Alvin Hammond, do solemnly swear that I will faithfully execute... ...the office of president of the United States... ...and will to the best of my ability preserve, protect and defend... ...the Constitution of the United States, so help me God. Sir, follow me, please. Place your hand there (..)2013 White House Down