NOUN (4)

1. a harsh or humorous critic (sometimes intended as a facetious compliment);
- Example: "the honoree gave his roasters as good as he got"

2. a cook who roasts food;

3. flesh of a large young chicken over 3 1/2 lb suitable for roasting;

4. a special cooking pan for roasting;

The Collaborative International Dictionary of English v.0.48:

Roaster \Roast"er\, n.
   1. One who roasts meat.
      [1913 Webster]

   2. A contrivance for roasting.
      [1913 Webster]

   3. A pig, or other article of food fit for roasting.
      [1913 Webster]

WordNet (r) 3.0 (2006):

roaster
    n 1: a harsh or humorous critic (sometimes intended as a
         facetious compliment); "the honoree gave his roasters as
         good as he got"
    2: a cook who roasts food
    3: flesh of a large young chicken over 3 1/2 lb suitable for
       roasting
    4: a special cooking pan for roasting