Webster's Revised Unabridged Dictionary · 1913

Septenary

Septenary , adjective

[Latin septenairus, from septeni seven each, septem seven: compare French septénaire. See Seven. ]

1.
Consisting of, or relating to, seven; as, a septenary number. — I. Watts
2.
Lasting seven years; continuing seven years.
Septenary penance. — Fuller

Septenary , noun

The number seven. [Rare] — Holinshed