mid-14c., "slight refreshment," originally taken in the afternoon, from none "noon" (see noon) + shench "draught, cup," from Old English scenc, related to scencan "to pour out, to give to drink," cognate with Old Frisian skenka "to give to drink, German, Dutch schenken "to give." Cf. luncheon.
Examples from the Web for nuncheon
We will eat our nuncheon, with your leave, in the castle hall.The House of Walderne
A. D. Crake
Luncheon, or "nuncheon" as some very ancient friends of mine always called it, was the merest mouthful.Collections and Recollections
George William Erskine Russell
This hour was called high noon, and the meal then taken was called a noonshun or nuncheon.