Abbreviation of 有給休暇 (paid vacation/paid leave). A common business term for days off during which salary is paid.
来週、有休を取って旅行に行く予定です。
I'm planning to take paid leave next week and go on a trip.
有休の残日数は社内システムで確認できます。
You can check your remaining paid leave days in the company's internal system.
有休を消化するために、長期休暇を申請した。
I applied for an extended leave to use up my paid vacation days.