de·fense | \ di-ˈfen(t)s ; as antonym of "offense" often ˈdē-ˌ \

Definition of defense 

(Entry 1 of 2)

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 defense

b law : the denial, answer, or plea (see plea sense 2b) of one against whom a criminal or civil action is brought : a defendant 's denial, answer, or plea

2a : capability of resisting attack the body's defense against disease

b sports : ability to keep an opponent from scoring in a game or contest : defensive play or ability a player known for good defense

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 structure

b : an argument in support or justification offered no defense of his actions

c 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 sense 3a)

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


defensed; defensing

Definition of defense (Entry 2 of 2)

transitive verb


: 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

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Other words from defense


defenseless \-ləs \ adjective
defenselessly adverb
defenselessness noun

Examples of defense in a Sentence


They put up a good defense, but the city ultimately fell to the invaders. They mounted a good defense. The city's defenses were not strong enough to keep out the invaders. We need to improve our defenses. the nation's air and ground defenses
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Recent Examples on the Web: Noun

After playing three grueling games, will Vrsaljko be able to force a fresh Mbappe back to play defense? John Kass,, "Joy of Chicago's Croatians cresting as World Cup final with France approaches," 13 July 2018 Should every new arrival be checked, with skin and gut swabs and lab tests, as part of hospital admission? Screening won’t be a perfect defense, because clinical microbiology is struggling with this bug. Maryn Mckenna, WIRED, "The Strange and Curious Case of the Deadly Superbug Yeast," 13 July 2018 In response to online bullies who have blamed Argento, who was dating the celebrity chef, for his death, Rose McGowan, Olivia Munn and more notable names in the entertainment industry have come to the actress' defense. Evan Real, The Hollywood Reporter, "Hollywood Stars Defend Asia Argento in Open Letter About Anthony Bourdain's Suicide," 13 July 2018 The Air Force also outsourced test design to a defense contractor that works on and has a vested interest in the F-35 program. Kyle Mizokami, Popular Mechanics, "The Long Awaited A-10 vs.-F-35 Flyoff Is Off to a Sketchy Start," 11 July 2018 The Suns held Orlando to 17-of-55 shooting on Monday night, while Reed scored 10 points, including two more 3-pointers, and played strong defense. Clevis Murray, azcentral, "Motivated Davon Reed looking toward redemption year with Suns," 10 July 2018 My teammates had my back and played great defense and were really rooting for me. Bob Narang, Lake County News-Sun, "Totally Tessitore: Dylan Tessitore pitches gem as Mundelein marks dominant win over Waukegan in summer regional," 9 July 2018 Those of us who would defend our nation’s environmental defenses, a vital yet under-appreciated legacy of the last half-century, need to examine the recent successes of anti-environmental conservatism and learn. Christopher Sellers, Vox, "How Republicans came to embrace anti-environmentalism," 6 July 2018 The House panel’s chairman, Rep. Devin Nunes, R-Calif., has also proven to be much more willing to jump to Trump’s defense, dedicating significant time to examining how the Justice Department has handled the Russian probe. Chris Megerian, Anchorage Daily News, "Senate panel backs up intelligence agencies, says Russia aimed to help Trump in election," 4 July 2018

Recent Examples on the Web: Verb

These are some of the questions that defense attorneys asked a Yale University student who brought a rape complaint against her classmate. Katie Reilly, Time, "A Yale Student Accused Her Classmate of Rape. His Lawyers Asked What She Was Wearing and How Much She Drank," 9 Mar. 2018 What does this mean for Kentucky’s defense moving forward? Joe Mussatto, ajc, "Kentucky Wildcats podcast: Staff news in Lexington while coaching rumors persist in Knoxville," 30 Nov. 2017 Among the concerns for the Aztecs coming into the game was how to defense Boise State’s quarterback(s). Kirk Kenney,, "No. 19 Aztecs' winning streak ends in 31-14 loss to Boise State," 15 Oct. 2017 In fact, the alliance had long ago set a goal that each member would devote at least 2 percent of GDP to defense in their own budgets. The Washington Post, Twin Cities, "Trump bid to smooth relations with Merkel complicated by policy, personal differences," 17 Mar. 2017 PHILADELPHIA — Sharks defense partners Brent Burns and Paul Martin have a pretty special relationship. Curtis Pashelka, The Mercury News, "Sharks’ Paul Martin having a role in Brent Burns’ success," 10 Feb. 2017 The Lakers cut the lead to 10 in the third quarter and to 12 in the fourth, but no one other than Jordan Clarkson could give the surging Clippers defense any problems. Dan Woike, Orange County Register, "‘Unstoppable’ DeAndre Jordan dominates as Clippers beat Lakers, 113-97," 14 Jan. 2017 Trump has called for massive hikes to defense spending and harsh cuts to domestic agencies in his 2018 budget, a proposal that many Republicans have rejected out of hand. The Washington Post, The Denver Post, "Congress passes spending deal to keep the federal government open another week," 28 Apr. 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'defense.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of defense


14th century, in the meaning defined at sense 1a


1932, in the meaning defined above

History and Etymology for defense


Middle English defense, defence, borrowed from Anglo-French defens, defense, defence, borrowed from Medieval Latin dēfensa, dēfensum (Late Latin dēfensa "vengeance"), nominal derivatives from feminine and neuter of Latin dēfensus, past participle of dēfendere "to ward off, defend"


derivative of defense entry 1

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Statistics for defense

Last Updated

19 Sep 2018

Look-up Popularity

Time Traveler for defense

The first known use of defense was in the 14th century

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More Definitions for defense



English Language Learners Definition of defense

: 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


de·fense | \ di-ˈfens \

Kids Definition of defense

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

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

Other words from defense

defenseless \-ləs \ adjective


variants: or chiefly British defence \di-ˈfen(t)s \

Medical Definition of defense 

: 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

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de·fense | \ di-ˈfens, ˈdē-ˌfens \

Legal Definition of defense 

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

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

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

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

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

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the setting in which something occurs

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