c.1300, "a fragment," from Old French esclis "splinter," a back-formation from esclicier "to splinter," from Frankish *slitan "to split" or some other Germanic source (cf. Old High German slizan; see slit). Meaning "piece cut from something" emerged early 15c. Meaning "a slicing stroke" (in golf, tennis) is recorded from 1886. Slice of life (1895) translates French tranche de la vie, a term from French Naturalist literature.
early 15c., from Middle French esclicier (see slice (n.)). Related: Sliced; slicing. Sliced bread introduced 1958; greatest thing since ... first attested 1969.
No matter how thick or how thin you slice it it's still baloney. [Carl Sandburg, "The People, Yes," 1936]