1911 Encyclopædia Britannica/Chaff

CHAFF (from the A.S. ceaf, allied to the O. High Ger. cheva, a husk or pod), the husks left after threshing grain, and also hay and straw chopped fine as food for cattle; hence, figuratively, the refuse or worthless part of anything. The colloquial use of the word, to chaff, in the sense of to banter or to make fun of a person, may be derived from this figurative sense, or from “to chafe,” meaning to vex or irritate.