Source : Webster's Revised Unabridged Dictionary (1913)

Offensive \Of*fen"sive\, a. [Cf.F. offensif. See {Offend}.]
   1. Giving offense; causing displeasure or resentment;
      displeasing; annoying; as, offensive words.

   2. Giving pain or unpleasant sensations; disagreeable;
      revolting; noxious; as, an offensive smell; offensive
      sounds. ``Offensive to the stomach.'' --Bacon.

   3. Making the first attack; assailant; aggressive; hence,
      used in attacking; -- opposed to {defensive}; as, an
      offensive war; offensive weapons.

   {League offensive and defensive}, a leaque that requires all
      the parties to it to make war together against any foe,
      and to defend one another if attacked.

   Syn: Displeasing; disagreeable; distasteful; obnoxious;
        abhorrent; disgusting; impertinent; rude; saucy;
        reproachful; opprobrious; insulting; insolent; abusive;
        scurrilous; assailant; attacking; invading. --
        {Of*fen"sive*ly}, adv. -- {Of*fen"sive*ness}, n.

Source : WordNet®

offensiveness
     n : the quality of being offensive [syn: {odiousness}, {distastefulness}]