Source : Webster's Revised Unabridged Dictionary (1913)

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

         A woman whose potluck was always to be relied on. --G.
                                                  Eliot.

   {To take potluck}, to take what food may chance to be
      provided.