Exact historical dictionary sense
Plan in Webster's 1913 dictionary
The 1913 record labels plan as noun. Its source-bounded etymology and selected historical definition appear below.
[F., fr. L. planus flat, level. See Plain, a.]
Cross-verified historical senseIn Webster's Revised Unabridged Dictionary (1913), "plan" is labeled noun. Its etymology is recorded as: "[F., fr. L. planus flat, level. See Plain, a.]" The selected historical definition says: "A draught or form; properly, a representation drawn on a plane, as a map or a chart; especially, a top view, as of a machine, or the representation or delineation of a horizontal section of anything, as of a building; a graphic representation; a diagram."