Source : Webster's Revised Unabridged Dictionary (1913)

Authorship \Au"thor*ship\, n.
   1. The quality or state of being an author; function or
      dignity of an author.

   2. Source; origin; origination; as, the authorship of a book
      or review, or of an act, or state of affairs.

Source : WordNet®

authorship
     n 1: the act of creating written works; "writing was a form of
          therapy for him"; "it was a matter of disputed
          authorship" [syn: {writing}, {composition}, {penning}]
     2: the act of initiating a new idea or theory or writing; "the
        authorship of the theory is disputed" [syn: {paternity}]