Source : Webster's Revised Unabridged Dictionary (1913)

Public-spirited \Pub"lic-spir`it*ed\, a.
   1. Having, or exercising, a disposition to advance the
      interest of the community or public; as, public-spirited
      men.

   2. Dictated by a regard to public good; as, a public-spirited
      project or measure. --Addison. -- {Pub"lic-spir`it*ed*ly},
      adv. -- {Pub"lic-spir`it*ed*ness}, n.

Source : WordNet®

public-spirited
     adj : showing unselfish interest in the public welfare; "a
           public-spirited citizen"