defense

UK: /ˈdiːfɛns/

US: /dɪˈfɛns or, esp. for sport, ˈdifɛns/

US: (di fens′ or, esp. for 7, 9, dē′fens)

Inflections of 'defense' (v): (⇒ conjugate)

defenses

v 3rd person singular

defensing

v pres p

defensed

v past

defensed

v past p

WordReference Random House Learner's Dictionary of American English © 2025

de•fense /dɪˈfɛns or, esp. for 7., ˈdifɛns/   n., v., -fensed, -fens•ing. 
n. 

1. a means of defending:
   [uncountable] a weapon of defense.
2. something that defends or protects:
   [countable] We'll have to strengthen our border defenses.
3. the arms production of a nation:
   [uncountable] spending billions on defense.
4. the defending of a cause by argument:
   [uncountable] to speak in defense of anti-pollution laws.
5. an argument defending some cause:
   [countable] The speech was a brilliant defense of the notion of civil rights for all.
6. Law [ count;
   usually singular;
   often: the + ~]
   • the strategy adopted by a defendant for defending against the plaintiff 's charge:
     We'll base our defense on the testimony of the two witnesses.
7. Psychology defense mechanism.
8. Sport [countable]
   • the tactics or strategy of defending against attack.
   • the players or team attempting to resist the attack of a team having the ball, puck, etc.

v. [~ + object]

9. to defend against (an opponent, play, etc.).

de•fense•less, adj. See -fend-.

WordReference Random House Unabridged Dictionary of American English © 2025

de•fense  (di fens′ or, esp. for 7, 9, dē′fens), n., v., -fensed, -fens•ing. 
n. 

1. resistance against attack;
   protection:
   Two more regiments are needed for the defense of the city.
2. something that defends, as a fortification, physical or mental quality, or medication:
   This fort was once the main defense of the island.
3. the defending of a cause or the like by speech, argument, etc.:
   He spoke in defense of the nation's foreign policy.
4. a speech, argument, etc., in vindication:
   She delivered a defense of free enterprise.
5. Law
   • the denial or pleading of the defendant in answer to the claim or charge that has been made.
   • the proceedings adopted by a defendant, or the defendant's legal agents, for defending against the charges that have been made.
   • a defendant and his or her counsel.
6. Psychology See defense mechanism (def. 2).
7. Sport
   • the practice or art of defending oneself or one's goal against attack, as in fencing, boxing, soccer, or football.
   • the team attempting to thwart the attack of the team having the ball or puck.
   • the players of a team who line up in their own defensive zone.
   • the positions on the field, ice, etc., taken by such players.
8. Government (cap.) Also called Defense′ Depart′ment. [Informal.] the Department of Defense.

v.t. 

9. Sport to defend against (an opponent, play, or tactic).

Also,[esp. Brit.,] defence. 

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

de•fense′less, adj. 
de•fense′less•ly, adv. 
de•fense′less•ness, n. 
Synonyms

• 1. security, preservation, safeguard.
• 3. support, advocacy, justification.

WordReference Random House Unabridged Dictionary of American English © 2025

de•fence  (di fens′), n., v.t., -fenced, -fenc•ing. [Chiefly Brit.]

1. British Terms defense.

de•fence′a•ble, adj. 
de•fence′less, adj. 
de•fence′less•ly, adv. 
de•fence′less•ness, n. 

Collins Concise English Dictionary © HarperCollins Publishers::

defence, defense / dɪˈfɛns/ noun

1. resistance against danger, attack, or harm; protection
2. a person or thing that provides such resistance
3. a plea, essay, speech, etc, in support of something; vindication; justification
4. a country's military measures or resources
5. a defendant's denial of the truth of the allegations or charge against him or her
6. the defendant and his or her legal advisers collectively
   Compare prosecution
7. the defence ⇒ the action of protecting oneself, one's goal, or one's allotted part of the playing area against an opponent's attacks
8. the players in a team whose function is to do this
9. (usually preceded by the) the team that does not have possession of the ball
10. the members of a team that play in such circumstances
11. See defence mechanism
12. (plural) fortifications

Etymology: 13th Century: from Old French, from Late Latin dēfensum, past participle of dēfendere to defend

deˈfenceless, deˈfenseless adjective