What is "undermeal"

Undermeal \Un"der*meal`\, n. [AS. under under + m?l part or portion; cf. AS. underm?l midday. See Under, Meal a part, and cf. Undern.]

1. The inferior, or after, part of the day; the afternoon.

   In undermeals and in mornings.
   --Chaucer.

2. Hence, something occurring or done in the afternoon; esp., an afternoon meal; supper; also, an afternoon nap; a siesta. [Obs. or Prov. Eng.]

   Another great supper, or undermeal, was made ready for them, coming home from ditching and plowing.
   --Withals (1608).

   I think I am furnished with Cattern [Catharine] pears for one undermeal.
   --B. Jonson.

   In a narrower limit than the forty years' undermeal of the seven sleepers.
   --Nash.

n. 1 (context UK dialectal obsolete English) The afternoon. 2 (context UK dialectal obsolete English) Something occurring or done in the afternoon, especially an afternoon meal, but also a nap, etc.