to guard, protect, (a person, thing)
protect
Cases of word usage
1) a reason given (true or invented) to explain or defend one's behaviour or actions (excuse)
2) to defend oneself from attacker, a hit etc (fend)
3) the ability to hear; an opportunity to defend oneself (hearing)
4) a person who loves and is ready to defend her or his country (patroit)
5) a wild bank of earth built to defend a fort etc (rampart)