Source : Webster's Revised Unabridged Dictionary (1913)

Officious \Of*fi"cious\, a. [L. officiosus: cf.F. officieux. See
   {Office}.]
   1. Pertaining to, or being in accordance with, duty. [R.]

            If there were any lie in the case, it could be no
            more than as officious and venial one. --Note on
                                                  Gen. xxvii.
                                                  (Douay
                                                  version).

   2. Disposed to serve; kind; obliging. [Archaic]

            Yet not to earth are those bright luminaries
            Officious.                            --Milton.

            They were tolerably well bred, very officious,
            humane, and hospitable.               --Burke.

   3. Importunately interposing services; intermeddling in
      affairs in which one has no concern; meddlesome.

            You are too officious In her behalf that scorns your
            services.                             --Shak.

   Syn: Impertinent; meddling. See {Impertinent}. --
        {Of*fi"cious*ly}, adv. -- {Of*fi"cious*ness}, n.

Source : WordNet®

officiousness
     n : aggressiveness as evidenced by intruding; by advancing
         yourself or your ideas without invitation [syn: {intrusiveness},
          {meddlesomeness}]