Sex*en"ni*al (?), a. [L. sexennium a period of six years, sexennis of six years; sex six + annus a year. See Six, and Annual.] Lasting six years, or happening once in six years. -- n. A sexennial event.

Sex*en"ni*al (?), a. [L. sexennium a period of six years, sexennis of six years; sex six + annus a year. See Six, and Annual.] Lasting six years, or happening once in six years. -- n. A sexennial event.