From Longman Business Dictionary
sabbaticalsab·bat·i·cal /səˈbætɪkəl/ noun [countableC, uncountableU]HUMAN RESOURCES a period of time when someone, especially someone in a university teaching job, stops doing their usual work in order to work in business, to study, or travelHe spent his sabbatical from Stanford University studying computer applications in finance.
—sabbatical adjectiveadjShe’s on sabbatical leave.