sabbatical year

noun

1. Also called sabbatical leave. (in a school, college, university, etc.) a year, usually every seventh, of release from normal teaching duties granted to a professor, as for study or travel.
2. Chiefly Biblical. a yearlong period to be observed by Jews once every seven years, during which the fields were to be left untilled and all agricultural labors were to be suspended. Lev. 25.Compare jubilee(def 6).

noun

1. (often capitals) Bible a year during which the land was to be left uncultivated, debts annulled, etc, supposed to be observed every seventh year by the ancient Israelites according to Leviticus 25