Emily Dickinson Lexicon

LUNCH, or LUNCH'EON, n. [W. llwnc, a gulp, a swallow, the gullet; Arm. louncqa, longein, to swallow greedily.]

Literally, a swallow; but in usage, a portion of food taken at any time, except at a regular meal. It is not unusual to take a luncheon before dinner. The passengers in the line-ships regularly have their lunch. I sliced the luncheon from the barley loaf. – Gay.