(archaic) A quantity of food set on a table at one time; provision of food for a person or party for one meal; also, the food given to an animal at one time.
(collective) A number of persons who eat together, and for whom food is prepared in common, especially military personnel who eat at the same table.
A building or room in which mess is eaten.
A set of four (from the old practice of dividing companies into sets of four at dinner).