Dictionary.com
Thesaurus.com
Synonyms

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.


verb (used with object)

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

Other Word Forms

Derived Forms

Inflected Forms

Nouns


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."

Keep Reading on Vocabulary.com

Vocabulary lists containing defense

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

See Examples For:

The Dolphins’ defense was up to the task against Hamilton’s highly touted quarterback Thaddeus Breaux, intercepting two of his passes and sacking him four times.

From Los Angeles Times ● Oct. 17, 2026

The sixth-year forward who starred at Sierra Canyon High has made an impact on defense and hopes to return from a foot injury for preseason finale on Friday.

From Los Angeles Times ● Oct. 17, 2026

For Atlanta, Reese’s sudden availability offered a chance to buy low on a two-time All Star whose tenacious defense and relentless rebounding could put them over the top.

From The Wall Street Journal ● Oct. 16, 2026

Among other sectors, spending on defense military programs increased by $48 billion, or six percent, over the year to $917 billion.

From Barron's ● Oct. 16, 2026

Their main argument, in defense of subprime CDOs, was that “the CDO buyer will never go away.”

From "The Big Short" by Michael Lewis

One crucial capability: American surveillance can give a very detailed picture of Russian air defenses through the systems’ electromagnetic signatures, said Withington.

From The Wall Street Journal ● Oct. 15, 2026

Further testing will be necessary to establish whether these modified defenses work effectively in whole plants and under agricultural conditions.

From Science Daily ● Oct. 15, 2026

Although researchers are still learning how these receptors operate, they appear to offer additional opportunities for strengthening plant defenses.

From Science Daily ● Oct. 15, 2026

Nobody gets a quote on air defenses for a server farm unless the server farm has enemies.

From MarketWatch ● Oct. 14, 2026

The sheriff claims the breach in the defenses has been repaired, but with the horde that Gideon described on the way, I want to see for myself.

From "Dread Nation" by Justina Ireland

Gilman started all five games for the Chargers this season with 22 tackles and three passes defensed.

From Los Angeles Times ● Oct. 7, 2025

This is his sixth season, all with the Chargers, and for his career has five interceptions and 21 passes defensed.

From Los Angeles Times ● Oct. 7, 2025

In six seasons, Oliver has three interceptions, 36 passes defensed, two sacks, nine quarterback hits and two fumble recoveries.

From Seattle Times ● Mar. 11, 2024

His six passes defensed are two off his career high with a half-dozen games remaining.

From Seattle Times ● Dec. 1, 2023

You know how it is said to Jeremiah, "Behold, I have made thee this day a defensed city, and an iron pillar, and brazen walls, against the whole land."

From Lectures on Architecture and Painting Delivered at Edinburgh in November 1853 by John Ruskin

It's also impossible not to look at the fact we could of and should have done a better job of defensing it.

From Seattle Times ● Dec. 8, 2011

Random Word

Spin the wheel and learn a new word!

Get a word

Vocabulary.com logo
by dictionary.com

Dictionary.com's Learning Companion

Go beyond just looking up words.
Remember them forever with VocabTrainer.

Start training