Definition of "Defense" :
noun: the act of defending someone or something against attack or injury
"A good boxer needs a good defense."
noun: protection from harm
"Sanitation is the best defense against disease."
noun: (military) military action or resources protecting a country against potential enemies
"They died in the defense of Stalingrad."
noun: a defendant's answer or plea denying the truth of the charges against him
"He gave evidence for the defense."
noun: a structure used to defend against attack
"The artillery battered down the defenses."
noun: the justification for some act or belief
"He offered a persuasive defense of the theory."
noun: the speech act of answering an attack on your assertions
"In defense he said the other man started it."
noun: an organization of defenders that provides resistance against attack
"He joined the defense against invasion."
noun: the defendant and his legal advisors collectively
"The defense called for a mistrial."
noun: (sports) the team that is trying to prevent the other team from scoring
"His teams are always good on defense."
noun: the federal department responsible for safeguarding national security of the United States; created in 1947
noun: (psychiatry) an unconscious process that tries to reduce the anxiety associated with instinctive desires