defense

American  

[dih-fens, dee-fens] / dɪˈfɛns, ˈdi fɛns /

noun

defenses plural

1. resistance against attack; protection.

   Two more regiments are needed for the defense of the city.

   Synonyms:

   safeguard, security

2. something that guards against harm, such as a fortification, physical or mental quality, or medication.

   This fort was once the main defense of the island.

3. the support of a cause or the like by speech, argument, etc..

   He spoke in defense of the nation's foreign policy.

   Synonyms:

   justification, advocacy, support

4. a speech, argument, etc., in vindication.

   She delivered a defense of free enterprise.

5. Law.

   1. the denial or pleading of the defendant in answer to the claim or charge that has been made.

   2. the proceedings adopted by a defendant or the defendant's legal agents, for defending against the charges that have been made.

   3. a defendant and their counsel.

6. Psychology. defense mechanism.

7. Sports.

   1. the practice or art of shielding oneself or one's goal from attack, as in fencing, boxing, soccer, or football.

   2. the team attempting to thwart the attack of the team having the ball or puck.

   3. the players of a team who line up in their own defensive zone.

   4. the positions on the field, ice, etc., taken by such players.

8. Also called Defense Department.  (initial capital letter) the Department of Defense.

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verb (used with object)

defensed, defensing

1. Sports. to defend against (an opponent, play, or tactic).

Other Word Forms

Derived Forms

• defenselessness
  noun
• nondefense
  noun
• predefense
  noun
• defenseless
  adjective
• undefensed
  adjective
• defenselessly
  adverb

Inflected Forms

Nouns

• defenses
  plural

Etymology

Origin of defense

First recorded in 1250–1300; Middle English from Old French from Late Latin dēfēnsa “a forbidding,” noun use of feminine of past participle of Latin dēfendere “to defend ”; replacing Middle English defens, from Anglo-French, Old French, from Medieval Latin defēnsum “(thing) forbidden,” neuter past participle of Latin dēfendere

Explanation

Defense has to do with protecting something or fighting against an opponent, whether it's national defense, a football team's defense, or a defense lawyer. Defense is the opposite of offense. It has to do with defending against all sorts of things: In the military, defense is about protecting a country from attack. In sports, defense is supposed to stop the other team from scoring. A defense attorney tries to prove his client is innocent. A defense can even be an excuse for doing something, as in "In my own defense, I was sleepwalking at the time."

Example Sentences

“There needs to be a real push to reconcile the entire defense industry—make it more efficient, have it produce more of what’s needed,” including air defense, deep precision strike and unmanned systems.

From The Wall Street Journal • Jul. 5, 2026

Pentagon Papers: New court documents show in detail the uneasy back-and-forth between Anthropic CEO Dario Amodei and Emil Michael, the undersecretary of defense for research and engineering.

From The Wall Street Journal • Jul. 5, 2026

The length and athleticism make Carr the type of rookie who could make an immediate impact on defense, Lakers summer league coach Ty Abbott said.

From Los Angeles Times • Jul. 4, 2026

“In total, the player, the defense, the hitting, the slugging, I think this is the best version of Max,” manager Dave Roberts said.

From Los Angeles Times • Jul. 3, 2026

“Don’t let that fool ya,” Benji said, coming to Felix’s defense.

From "Millionaires for the Month" by Stacey McAnulty