The Collaborative International Dictionary of English v.0.48:

Defence \De*fence"\ (d[-e]*f[e^]ns"), n. & v. t.
   See Defense.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Defense \De*fense"\, Defence \De*fence"\, n. [F. d['e]fense, OF.
   defense, fem., defens, masc., fr. L. defensa (cf. LL.
   defensum), from defendere. See Defend, and cf. Fence.]
   1. The act of defending, or the state of being defended;
      protection, as from violence or danger.
      [1913 Webster]

            In cases of defense 't is best to weigh
            The enemy more mighty than he seems.  --Shak.
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   2. That which defends or protects; anything employed to
      oppose attack, ward off violence or danger, or maintain
      security; a guard; a protection.
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            War would arise in defense of the right. --Tennyson.
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            God, the widow's champion and defense. --Shak.
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   3. Protecting plea; vindication; justification.
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            Men, brethren, and fathers, hear ye my defense.
                                                  --Acts xxii.
                                                  1.
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   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.
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   5. Act or skill in making defense; defensive plan or policy;
      practice in self defense, as in fencing, boxing, etc.
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            A man of great defense.               --Spenser.
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            By how much defense is better than no skill. --Shak.
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   6. Prohibition; a prohibitory ordinance. [Obs.]
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            Severe defenses . . . against wearing any linen
            under a certain breadth.              --Sir W.
                                                  Temple.
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The Collaborative International Dictionary of English v.0.48:

Defense \De*fense"\, v. t.
   To furnish with defenses; to fortify. [Obs.] [Written also
   defence.]
   [1913 Webster]

         Better manned and more strongly defensed. --Hales.
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WordNet (r) 3.0 (2006):

defence
    n 1: (psychiatry) an unconscious process that tries to reduce
         the anxiety associated with instinctive desires [syn:
         defense mechanism, defense reaction, defence
         mechanism, defence reaction, defense, defence]
    2: (sports) the team that is trying to prevent the other team
       from scoring; "his teams are always good on defense" [syn:
       defense, defence, defending team] [ant: offence,
       offense]
    3: the defendant and his legal advisors collectively; "the
       defense called for a mistrial" [syn: defense, defence,
       defense team, defense lawyers] [ant: prosecution]
    4: an organization of defenders that provides resistance against
       attack; "he joined the defense against invasion" [syn:
       defense, defence, defense force, defence force]
    5: the speech act of answering an attack on your assertions;
       "his refutation of the charges was short and persuasive"; "in
       defense he said the other man started it" [syn: refutation,
       defense, defence]
    6: the justification for some act or belief; "he offered a
       persuasive defense of the theory" [syn: defense, defence,
       vindication]
    7: a structure used to defend against attack; "the artillery
       battered down the defenses" [syn: defensive structure,
       defense, defence]
    8: a defendant's answer or plea denying the truth of the charges
       against him; "he gave evidence for the defense" [syn:
       defense, defence, denial, demurrer] [ant: criminal
       prosecution, prosecution]
    9: (military) military action or resources protecting a country
       against potential enemies; "they died in the defense of
       Stalingrad"; "they were developed for the defense program"
       [syn: defense, defence, defensive measure]
    10: protection from harm; "sanitation is the best defense
        against disease" [syn: defense, defence]
    11: the act of defending someone or something against attack or
        injury; "a good boxer needs a good defense"; "defense
        against hurricanes is an urgent problem" [syn: defense,
        defence]