Septennial
Pronunciation : Sep*ten"ni*al
Part of Speech : a.
Etymology : [L. septennium a period of seven years; septem seven + annus year. See Seven, and Annual.]
Definition : 1. Lasting or continuing seven years; as, septennial parliaments.
2. Happening or returning once in every seven years; as, septennial elections in England.
Source : Webster's Unabridged Dictionary, 1913