"fuss, trouble," 1945, American English (in "Down Beat" magazine), perhaps from U.S. Southern dialectal hassle "to pant, breathe noisily" (1928), of unknown origin; or perhaps from hatchel "to harass" (1800), which may be a variant of hazel, the name of the plant that furnished switches for whippings. Noted in 1946 as a show biz vogue word.