defend
Definitions
To resist an attack made on someone or something; to protect from harm or danger.
To speak or write in favor of an action or person; to justify or support an argument.
To attempt to maintain a title or championship in a competitive sport.
Examples
The lawyer worked tirelessly to defend his client in court.
Animals will often fight to defend their territory from intruders.
It is important to defend your beliefs when they are challenged by others.