The condition of having left or abandoned someone or someplace, often abruptly, under difficult or unpleasant circumstances, and with the implication of not intending to come back. Colloquial misspelling of "ran off." The term is derived from the movie O Brother, Where Art Thou
, in which an rather unlearned character wishes to convey to other characters that his wife left him but does not wish to say so aloud in front of his son.
Mrs. Hogwallop done r-u-n-n-o-f-t.