The Collaborative International Dictionary of English v.0.48:

Roast \Roast\, n.
   That which is roasted; a piece of meat which has been
   roasted, or is suitable for being roasted.
   [1913 Webster]

         A fat swan loved he best of any roost [roast].
                                                  --Chaucer.
   [1913 Webster]

   To rule the roast, to be at the head of affairs. "The
      new-made duke that rules the roast." --Shak.
      [1913 Webster]