Vacancy means an empty space or position that needs to be filled. When a hotel has a vacancy, it has an empty room available for guests. When a company has a vacancy, it needs to hire someone for an open job. The blinking “No Vacancy” sign at a roadside motel tells travelers that every room is occupied.

You'll see it on signs, in job listings, and in news about available positions. A school with a vacancy for a principal needs someone to fill that leadership role. An apartment building might advertise vacancies when units are available to rent.

Vacant is the adjective form: a vacant seat on the bus is empty and available. A vacant lot is an empty piece of land with no building on it. When someone has a vacant stare, their eyes look empty or unfocused, as if their mind is somewhere else. That last meaning captures something important about the word: vacancy describes the absence of something that should be there, whether that's a person in a seat, a building on land, or focus in someone's eyes.