noun de·fense \di-ˈfen(t)s; as antonym of “offense,” often ˈdē-ˌ\

Definition of defense

  1. 1a :  the act or action of defending (see defend) the defense of our country speak out in defense of justice quickly jumped to her friend's defenseb law :  the denial, answer, or plea (see plea 2b) of one against whom a criminal or civil action is brought :  a defendant 's denial, answer, or plea

  2. 2a :  capability of resisting attack the body's defense against diseaseb sports :  ability to keep an opponent from scoring in a game or contest :  defensive play or ability a player known for good defense

  3. 3a :  means or method of defending or protecting oneself, one's team, or another the nation's air and ground defenses Big shells are an effective defense against these predators as well. — Gregory P. Dietl; also :  a defensive structureb :  an argument in support or justification offered no defense of his actionsc law :  the collected facts and method adopted by a defendant to protect and defend against a plaintiff's action His lawyers used an insanity defense.d chess :  a sequence of moves available to the second player in the opening (see opening 3a)

  4. 4a law :  a defending party or group (as in a court of law) The defense rests.b sports :  a defensive team He was the linchpin of one of the league's stoutest defenses … — Sarah Kwak

  5. 5 government :  the military and industrial aggregate that authorizes and supervises arms production appropriations for defense defense contract


play \-ləs\ adjective





Examples of defense in a Sentence

  1. They put up a good defense, but the city ultimately fell to the invaders.

  2. They mounted a good defense.

  3. The city's defenses were not strong enough to keep out the invaders.

  4. We need to improve our defenses.

  5. the nation's air and ground defenses

Origin and Etymology of defense

Middle English, from Anglo-French, from Late Latin defensa vengeance, from Latin, feminine of defensus, past participle of defendere —see defend



verb de·fense

Definition of defense





  1. transitive verb
  2. :  to take specific defensive action against (an opposing team or player or an offensive play) :  to attempt to keep (an opponent or play) from scoring in a game or contest The gangly Pressey was clearly Milwaukee's only real hope of defensing Bird … — Jack McCallum

Origin and Etymology of defense

see 1defense

Other General Sports Terms

DEFENSE Defined for English Language Learners



Definition of defense for English Language Learners

  • : the act of defending someone or something from attack

  • : something that is used to protect yourself, your country, etc.

  • : the act of speaking or writing in support of someone or something that is being attacked or criticized

DEFENSE Defined for Kids


noun de·fense \di-ˈfens\

Definition of defense for Students

  1. 1 :  the act of protecting or defending They were defeated in spite of a brave defense.

  2. 2 :  something that defends or protects … sneaking out to spy on him was not much of a defense against his treachery. — Lemony Snicket, The Austere Academy

  3. 3 :  the players on a team who try to stop the other team from scoring


\-ləs\ adjective

Medical Dictionary


noun de·fense
variants: or chiefly British



Medical Definition of defense

  1. :  a means or method of protecting the physical or functional integrity of body or mind ability to concentrate urine may be interpreted as a renal defense of body volume fluid—Jack Metcoff

Law Dictionary


noun de·fense \di-ˈfens, ˈdē-ˌfens\

Legal Definition of defense

  1. 1 :  the act or action of defending — see also self-defense

  2. 2a :  the theory or ground that forms the basis for a defendant's opposition to an allegation in a complaint or to a charge in a charging instrument (as an indictment); also :  the evidence and arguments presented supporting the defendant's opposition — see also accord, alibi, assumption of risk, coercion, consent, contributory negligence at negligence, denial, diminished capacity, duress, entrapment, estoppel, fraud, infancy, insanity, intoxication, laches, mistake, necessity, res judicata, statute of limitations absolute defense :  complete defense in this entry affirmative defense :  a defense that does not deny the truth of the allegations against the defendant but gives some other reason (as insanity, assumption of risk, or expiration of the statute of limitations) why the defendant cannot be held liable Editor's note: The defendant bears the burden of proof as to affirmative defenses. choice of evils defense :  a defense to a criminal charge based on the assertion that the criminal act was committed to avoid the commission of an even greater evil —called also lesser evils defense Editor's note: In jurisdictions that recognize the choice of evils defense, it encompasses both of the older defenses of duress and necessity. complete defense :  a defense that shields the defendant from any liability and bars any recovery by the plaintiff — compare partial defense in this entry lesser evils defense :  choice of evils defense in this entry meritorious defense :  a defense that is based on evidence sufficient to warrant setting aside a default judgment against the defendant in civil litigation partial defense :  a defense by which the defendant reduces the amount of damages of which he or she is liable — compare complete defense in this entry b :  a basis upon which an obligor of a negotiable instrument may avoid liability under the instrument personal defense :  a defense of an obligor under a negotiable instrument that can be asserted against anyone but a holder in due course real defense :  a defense of an obligor of a negotiable instrument that may be asserted even against a holder in due course Editor's note: Section 3-305(a)(1) of the Uniform Commercial Code sets out the real defenses as infancy, duress, lack of legal capacity, illegality of the transaction, fraud in the factum, and discharge of the obligor by a bankruptcy court. By exclusion, all other defenses are personal defenses.

  3. 3 :  the defending side in a legal proceeding the defense rests — compare prosecution

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to reach the highest or a decisive point

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