septennial

Occurring every seven years.

Consisting of or continuing for seven years.

An event that occurs every seven years.

Lasting or continuing seven years: as, septennial parliaments.

Occurring or returning once in every seven years: as, septennial elections.

Lasting or continuing seven years.

Happening or returning once in every seven years.

Lasting or continuing seven years; as, septennial parliaments.

Happening or returning once in every seven years; as, septennial elections in England.