Английский Этимологический словарь - slice (n.)

- 13c., from O.Fr. esclis "splinter," from esclicier "to splinter," from Frank. *slitan "to split." Meaning "piece cut from something" emerged early 15c. The verb is 1475, from M.Fr. esclicier. Sliced bread introduced 1958; greatest thing since ... first attested 1969.