Definition of: defense

(di·fens′) noun
1. The act of defending; protection; the state of being defended.
2. Anything that defends.
3. A plea in justification; excuse; apology.
4. Law An opposing or denying of the truth, validity, or sufficiency of a plaintiff's complaint; also, whatever is alleged, pleaded, or offered in evidence as sufficient to defeat an action either wholly or in part.
5. The art or science of defending by force of arms; skilfulness in defending oneself, as in fencing or boxing.
6. Obs. A prohibitory decree. Also defence.
—Department of Defense An executive department of the U.S. government (established in 1947), headed by the Secretary of Defense and composed of the Department of the Army, the Department of the Navy, the Department of the Air Force, and various military agencies and staffs: from 1947 to 1949 called the National Military Establishment. [<OF <L defensus, pp. of defendere. See DEFEND.] Synonyms: apology, bulwark, exculpation, fortress, guard, justification, protection, ram-part, resistance, safeguard, shelter, shield, vindication. The weak may speak or act in defense of the strong; none but the powerful can assure others of protection. A defense is ordinarily against actual attack; protection is against possible as well as actual dangers. We speak of defense against an assault, protection from the cold. Vindication is a triumphant defense of character and conduct against charges of error or wrong. Compare APOLOGY, RAMPART. Antonyms: abandonment, betrayal, capitulation, desertion, flight, surrender.