undermeal

from The Century Dictionary.

• noun The meal eaten at undern, the chief meal of the day.
• noun The part or division of the day which included undern: originally the morning, later the afternoon.
• noun An after-dinner sleep; a siesta taken in the afternoon.

from the GNU version of the Collaborative International Dictionary of English.

• noun Obs. or Prov. Eng. The inferior, or after, part of the day; the afternoon.
• noun Obs. or Prov. Eng. Hence, something occurring or done in the afternoon; esp., an afternoon meal; supper; also, an afternoon nap; a siesta.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun obsolete, UK, dialect The inferior, or after, part of the day; the afternoon.
• noun obsolete, UK, dialect Something occurring or done in the afternoon; an afternoon meal, nap, etc.