Full Idea
A work of art is an artifact of a kind created to be presented to an artworld public.
Gist of Idea
A work of art is an artifact created for the artworld
Source
George Dickie (The New Institutional Theory of Art [1983], p.53)
A Reaction
This is the culminating definition in his paper, deriving originally from Danto, and an improvement of his earlier more complex definition. Since this definition amounts to 'this is art if I say it is art', it doesn't seem to reveal much.
Book Reference
'Aesthetics and the Phil of Art (Analytic trad)', ed/tr. Lamarque,P/Olsen,SH [Blackwell 2004], p.53