Source : Webster's Revised Unabridged Dictionary (1913)

Luncheon \Lunch"eon\, n. [Prov. E. luncheon, lunchion, lunshin,
   a large lump of food, fr. lunch. See {Lunch}.]
   1. A lump of food. [Prov. Eng.]

   2. A portion of food taken at any time except at a regular
      meal; an informal or light repast, as between breakfast
      and dinner.

Luncheon \Lunch"eon\, v. i.
   To take luncheon. --Beaconsfield.

Source : WordNet®

luncheon
     n : a midday meal [syn: {lunch}, {tiffin}, {dejeuner}]