Enneatic \En`ne*at"ic\, Enneatical \En`ne*at"ic*al\, a. [Gr. ? nine.]

Occurring once in every nine times, days, years, etc.; every ninth.

Enneatical day, every ninth day of a disease.

Enneatical year, every ninth year of a man's life.

Source: Webster's Revised Unabridged Dictionary (1913)