potluck

from WordNet (r) 3.0 (2006)

potluck
    n 1: whatever happens to be available especially when offered to
         an unexpected guest or when brought by guests and shared by
         all; "having arrived unannounced we had to take potluck";
         "a potluck supper"

from The Collaborative International Dictionary of English v.0.48

Potluck \Pot"luck`\, n.
   Whatever may chance to be in the pot, or may be provided for
   a meal.
   [1913 Webster]

         A woman whose potluck was always to be relied on. --G.
                                                  Eliot.
   [1913 Webster]

   {To take potluck}, to take what food may chance to be
      provided.
      [1913 Webster]