This word is acceptable for play in the US & UK dictionaries that are being used in the following games:

• Lexulous
• Wordscraper
• Wordosaur

adj. Consisting of or containing seven.

adj. Of seventh rank or order.

adj. Consisting of, or relating to, seven.

adj. Lasting seven years; continuing seven years.

n. The number seven.

Consisting of or relating to seven: as, a septenary number.

Lasting seven years; occurring once in seven years: as, a septenary term; a septenary council.

n. The number seven; the heptad.

n. A group of seven things.

n. the cardinal number that is the sum of six and one

"One of the oldest lines of modern English verse is the so-called septenary (septenarius), having had a nearly continuous tradition from the twelfth-century Poema Morale down (in its divided form) to the present."

digit    figure   

octonary    binary    vigenary    denary    secondary   

many-rayed    1-to-5    motor-rifle    Slave State    whole-tone