1911 Encyclopædia Britannica/Mess

MESS (an adaptation of O. Fr. mes, mod. mets; Ital. messo; derived from the Late Lat. missum, past participle of mittere “to send or place in position”), a service of meat, a dish sent to table. The term is also used of the persons who are in the habit of eating their meals together, and thus particularly of the parties into which a ship’s company or a regiment is divided, either according to their rank, or for convenience in catering. Originally, a mess in this sense was a group of four persons sitting at one table and helped from the same dishes. In the Inns of Court, London, the original number is preserved, four benchers or four students dining together.

In early times the word mess was applied to food of a more or less liquid character, as soup, porridge, broth, &c. It is probably in allusion to the sloppy nature of semi-liquid messes of food that a mess has come also to mean a state of disorder, confusion and discomfort. Skeat takes the word in this sense to be a variant of “mash,” originally to mix up.