A lot vs. Alot: 9 Grammatical Pitfalls
1945, American English, 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.
1951, from hassle (n.). Related: Hassled; hassling.
[1920s+, but mainly 1940s+; origin unknown; probably fr hatchel, ''to harass,'' found by 1800, a hatchel being an instrument for beating flax, and related to heckle;perhaps fr hazel, with a variant hassle, the switch used for beatings; hazel oil meant ''a beating'' by 1678]