WordReference Random House Learner's Dictionary of American English © 2026
de•fense /dɪˈfɛns or, esp. for 7., ˈdifɛns/USA pronunciation
n., v., -fensed, -fens•ing.
n.
v. [~ + object]
WordReference Random House Unabridged Dictionary of American English © 2026n.
- a means of defending:[uncountable]a weapon of defense.
- something that defends or protects:[countable]We'll have to strengthen our border defenses.
- the arms production of a nation:[uncountable]spending billions on defense.
- the defending of a cause by argument:[uncountable]to speak in defense of anti-pollution laws.
- an argument defending some cause:[countable]The speech was a brilliant defense of the notion of civil rights for all.
- 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.
- Psychologydefense mechanism.
- 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]
- to defend against (an opponent, play, etc.).
de•fense
(di fens′ or, esp. for 7, 9, dē′fens),USA pronunciation n., v., -fensed, -fens•ing.
n.
v.t.
de•fense′less, adj.
de•fense′less•ly, adv.
de•fense′less•ness, n.
n.
- resistance against attack;
protection:Two more regiments are needed for the defense of the city. - something that defends, as a fortification, physical or mental quality, or medication:This fort was once the main defense of the island.
- the defending of a cause or the like by speech, argument, etc.:He spoke in defense of the nation's foreign policy.
- a speech, argument, etc., in vindication:She delivered a defense of free enterprise.
- 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.
- PsychologySee defense mechanism (def. 2).
- 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.
- Government(cap.) Also called Defense′ Depart′ment. [Informal.]the Department of Defense.
v.t.
- Sportto defend against (an opponent, play, or tactic).
- 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•ly, adv.
de•fense′less•ness, n.
- 1. security, preservation, safeguard. 3. support, advocacy, justification.
'defenseless' also found in these entries (note: many are not synonyms or translations):