Septennial

• (a.) Happening or returning once in every seven years; as, septennial elections in England. • (a.) Lasting or continuing seven years; as, septennial parliaments.
Found on http://thinkexist.com/dictionary/meaning/septennial/

Septennial

Sep·ten'ni·al adjective [ Latin septennium a period of seven years; septem seven + annus year. See Seven , and Annual .] 1. Lasting or continuing seven years; as, septennial parliaments. 2. Happening or returning once in every seven years;...
Found on http://www.encyclo.co.uk/webster/S/70

Septennial

Septennial describes something lasting seven years.
Found on http://www.probertencyclopaedia.com/browse/AS.HTM
No exact match found