The Collaborative International Dictionary of English v.0.48:

Officious \Of*fi"cious\, a. [L. officiosus: cf. F. officieux.
   See Office.]
   1. Pertaining to, or being in accordance with, duty. [R.]
      [1913 Webster]

            If there were any lie in the case, it could be no
            more than an officious and venial one. --Note on
                                                  Gen. xxvii.
                                                  (Douay
                                                  version).
      [1913 Webster]

   2. Disposed to serve; kind; obliging. [Archaic]
      [1913 Webster]

            Yet not to earth are those bright luminaries
            Officious.                            --Milton.
      [1913 Webster]

            They were tolerably well bred, very officious,
            humane, and hospitable.               --Burke.
      [1913 Webster]

   3. Importunately interposing services; intermeddling in
      affairs in which one has no concern; meddlesome.
      [1913 Webster]

            You are too officious
            In her behalf that scorns your services. --Shak.
      [1913 Webster]

   Syn: Impertinent; meddling. See Impertinent.
        [1913 Webster] -- Of*fi"cious*ly, adv. --
        Of*fi"cious*ness, n.
        [1913 Webster]

WordNet (r) 3.0 (2006):

officiousness
    n 1: aggressiveness as evidenced by intruding; by advancing
         yourself or your ideas without invitation [syn:
         intrusiveness, meddlesomeness, officiousness]