Exact historical dictionary sense
September in Webster's 1913 dictionary
The 1913 record labels september as noun. Its source-bounded etymology and selected historical definition appear below.
[L., fr. septem seven, as being the seventh month of the Roman year, which began with March: cf. F. septembre. See Seven.]
Cross-verified historical senseIn Webster's Revised Unabridged Dictionary (1913), "september" is labeled noun. Its etymology is recorded as: "[L., fr. septem seven, as being the seventh month of the Roman year, which began with March: cf. F. septembre. See Seven.]" The selected historical definition says: "The ninth month of the year, containing thurty days."