The noun defense has 11 senses (first 11 from tagged texts)
1. (386) defense, defence, defending team -- ((sports) the team that is trying to prevent the other team from scoring; "his teams are always good on defense")
2. (327) defense, defence, defensive measure -- (military action or resources protecting a country against potential enemies; "they died in the defense of Stalingrad"; "they were developed for the defense program")
3. (281) defense, defence, defense team, defense lawyers -- (the defendant and his legal advisors collectively; "the defense called for a mistrial")
4. (40) defense, defence -- (protection from harm; "sanitation is the best defense against disease")
5. (36) defensive structure, defense, defence -- (a structure used to defend against attack; "the artillery battered down the defenses")
6. (29) refutation, defense, defence -- (the speech act of answering an attack on your assertions; "his refutation of the charges was short and persuasive"; "in defense he said the other man started it")
7. (23) defense, defence, vindication -- (the justification for some act or belief; "he offered a persuasive defense of the theory")
8. (20) defense, defence, denial, demurrer -- (a defendant's answer or plea denying the truth of the charges against him; "he gave evidence for the defense")
9. (17) defense, defence, defense force, defence force -- (an organization of defenders that provides resistance against attack; "he joined the defense against invasion")
10. (10) Department of Defense, Defense Department, United States Department of Defense, Defense, DoD -- (the federal department responsible for safeguarding national security of the United States; created in 1947)
11. (6) defense mechanism, defense reaction, defence mechanism, defence reaction, defense, defence -- ((psychiatry) an unconscious process that tries to reduce the anxiety associated with instinctive desires)