Exact historical dictionary sense
Shift in Webster's 1913 dictionary
The 1913 record labels shift as noun. Its source-bounded etymology and selected historical definition appear below.
[Cf. Icel. skipti. See Shift, v. t.]
Cross-verified historical senseIn Webster's Revised Unabridged Dictionary (1913), "shift" is labeled noun. Its etymology is recorded as: "[Cf. Icel. skipti. See Shift, v. t.]" The selected historical definition says: "The act of shifting."