The Collaborative International Dictionary of English v.0.48:

Offense \Of*fense"\, Offence \Of*fence"\, n. [F., fr. L.
   offensa. See Offend.]
   1. The act of offending in any sense; esp., a crime or a sin,
      an affront or an injury.
      [1913 Webster]

            Who was delivered for our offenses, and was raised
            again for our justification.          --Rom. iv. 25.
      [1913 Webster]

            I have given my opinion against the authority of two
            great men, but I hope without offense to their
            memories.                             --Dryden.
      [1913 Webster]

   2. The state of being offended or displeased; anger;
      displeasure; as, to cause offense.
      [1913 Webster]

            He was content to give them just cause of offense,
            when they had power to make just revenge. --Sir P.
                                                  Sidney.
      [1913 Webster]

   3. A cause or occasion of stumbling or of sin. [Obs.]
      [1913 Webster]

            Woe to that man by whom the offense cometh! --Matt.
                                                  xviii. 7.
      [1913 Webster]

   4. In any contest, the act or process of attacking as
      contrasted with the act of defending; the offensive; as,
      to go on the offense.
      [PJC]

   5. (Sports) The members of a team who have the primary
      responsibility to score goals, in contrast to those who
      have the responsibility to defend, i.e. to prevent the
      opposing team from scoring goal.
      [PJC]

   Note: This word, like expense, is often spelled with a c. It
         ought, however, to undergo the same change with
         expense, the reasons being the same, namely, that s
         must be used in offensive as in expensive, and is found
         in the Latin offensio, and the French offense.
         [1913 Webster]

   To take offense, to feel, or assume to be, injured or
      affronted; to become angry or hostile.

   Weapons of offense, those which are used in attack, in
      distinction from those of defense, which are used to
      repel.
      [1913 Webster]

   Syn: Displeasure; umbrage; resentment; misdeed; misdemeanor;
        trespass; transgression; delinquency; fault; sin; crime;
        affront; indignity; outrage; insult.
        [1913 Webster]

WordNet (r) 3.0 (2006):

offense
    n 1: a lack of politeness; a failure to show regard for others;
         wounding the feelings or others [syn: discourtesy,
         offense, offence, offensive activity]
    2: a feeling of anger caused by being offended; "he took offence
       at my question" [syn: umbrage, offense, offence]
    3: (criminal law) an act punishable by law; usually considered
       an evil act; "a long record of crimes" [syn: crime,
       offense, criminal offense, criminal offence, offence,
       law-breaking]
    4: the team that has the ball (or puck) and is trying to score
       [syn: offense, offence] [ant: defence, defending
       team, defense]
    5: the action of attacking an enemy [syn: offense, offence,
       offensive]

Moby Thesaurus II by Grady Ward, 1.0:

151 Moby Thesaurus words for "offense":
   affront, aggravated assault, aggression, amphibious attack,
   angry look, armed assault, aspersion, assailing, assailment,
   assault, atrocity, attack, bad faith, banzai attack, blitz,
   blitzkrieg, breach, breach of contract, breach of faith,
   breach of privilege, breach of promise, breach of trust, breaking,
   breakthrough, brickbat, casus belli, charge, contempt,
   contravention, contumely, counterattack, counteroffensive,
   coup de main, crime, crime against humanity, crippling attack, cut,
   dead set at, deadly sin, delict, delinquency, dereliction,
   descent on, despite, dirty look, diversion, diversionary attack,
   drive, dudgeon, dump, enormity, error, evil, failure, fault,
   felony, flank attack, flout, flouting, frontal attack, frown,
   gas attack, genocide, gibe, glare, glower, guilty act,
   head-on attack, heavy sin, huff, humiliation, illegality,
   impropriety, indignity, indiscretion, inexpiable sin, infiltration,
   infraction, infringement, iniquity, injury, injustice, insult,
   jeer, jeering, lapse, lightning attack, lightning war, malefaction,
   malfeasance, malum, mass attack, megadeath, miff, minor wrong,
   misdeed, misdemeanor, misfeasance, mock, mockery, mortal sin,
   mugging, nonfeasance, offensive, omission, onset, onslaught,
   outrage, overkill, panzer warfare, peccadillo, peccancy, pique,
   provocation, push, put-down, raw nerve, red rag, resentment,
   run against, run at, rush, sally, scoff, scowl, scurrility,
   shock tactics, sin, sin of commission, sin of omission, sinful act,
   slip, snuff, sore point, sore spot, sortie, strike, taunt,
   tender spot, tort, transgression, trespass, trip, umbrage,
   uncomplimentary remark, unprovoked assault, unutterable sin,
   venial sin, violation, wrong, wrongdoing