The children played in the 'vacant lot' [=a piece of land that is not being used] between the two buildings.
There were no 'vacant' apartments in the building. [=there were no empty apartments available to be rented]
('Brit') I found my job through the 'situations vacant' [=('US') 'help wanted'] section of the newspaper.
(..) And you must be Miss Granger. Yes, Draco has told me all about you. And your parents. Muggles, aren't they? Let me see. Red hair, vacant expressions. . . . . .tatty, secondhand book. You must be the Weasleys. lt's mad in here. Let's go outside. -Well, well, well. Weasley senior. (..)2002 Harry Potter and the Chamber of Secrets