Webster's Revised Unabridged Dictionary · 1913

Defense

Defense , noun

[French défense, Old French defense, fem., defens, masc., from Latin defensa (compare Late Latin defensum), from defendere. See Defend, and compare Fence.]

1.
The act of defending, or the state of being defended; protection, as from violence or danger.
In cases of defense 't is best to weigh The enemy more mighty than he seems. — Shakespeare
2.
That which defends or protects; anything employed to oppose attack, ward off violence or danger, or maintain security; a guard; a protection.
War would arise in defense of the right. — Tennyson
God, the widow's champion and defense. — Shakespeare
3.
Protecting plea; vindication; justification.
Men, brethren, and fathers, hear ye my defense. — Acts xxii. 1
4.
(Law) The defendant's answer or plea; an opposing or denial of the truth or validity of the plaintiff's or prosecutor's case; the method of proceeding adopted by the defendant to protect himself against the plaintiff's action.
5.
Act or skill in making defense; defensive plan or policy; practice in self defense, as in fencing, boxing, etc.
A man of great defense. — Spenser
By how much defense is better than no skill. — Shakespeare
6.
Prohibition; a prohibitory ordinance. [Obsolete]
Severe defenses... against wearing any linen under a certain breadth. — Sir W. Temple

Also: Defence

Defense , transitive verb

To furnish with defenses; to fortify. [Obsolete]
Better manned and more strongly defensed. — Hales