sabbatical year

sabbatical year (plural sabbatical years)

1. A year of rest for the land observed every seven years in ancient Judea, which included allowing the fields to lie without tilling, sowing, or reaping from one autumn to the next in accordance with a Levitical commandment.
2. A leave, often with full or half pay granted (as every seventh year) to one holding an administrative or professional position for rest, travel, or research.