What is 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 called?

enneatic — 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. (Webster's 1913.)

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