lunch

Recorded since 1580 in the sense “piece, hunk”. The word luncheon with the same meaning is presumably an extension on the pattern of puncheon (“cask”) and truncheon (“cudgel”). But earliest found forms of luncheon include lunshin and lunching, which are equivalent to lunch +‎ -ing, with the suffix -ing possibly later modified to imitate a French origin.

In contrast, the more common sense “light meal” is first attested for luncheon in 1652 and for lunch in 1829, so in this sense the latter is probably a shortening of the former.

Lunch is possibly a derivative of lump (as hunch is from hump. See hunch for more), or represents an alteration of nuncheon, from Middle English nonechenche (“light midday meal”) (see