1896, British student slang merger of breakfast and lunch.
ACCORDING to the Lady, to be fashionable nowadays we must "brunch." Truly an excellent portmanteau word, introduced, by the way, last year, by Mr GUY BERINGER, in the now defunct Hunter's Weekly, and indicating a combined breakfast and lunch. At Oxford, however, two years ago, an important distinction was drawn. The combination-meal, when nearer the usual breakfast hour, is "brunch," and, when nearer luncheon, is "blunch." Please don't forget this. ["Punch," Aug. 1, 1896]