Vacant and vacation are siblings, both children of Latin vacare, 'to be empty' or 'to be free from obligation'. Romans saw leisure as a kind of productive emptiness — time cleared of duties. When the word crossed into Anglo-French and then into English around 1290, it landed first in the courts: a vacant seat, a vacant parcel of land, a vacant benefice. The legal sense dominated for centuries. In the seventeenth century, writers began applying it to faces and gazes — a vacant stare implied a mind temporarily emptied of thought, like a room between tenants. The related vacuum, borrowed directly from Latin in the sixteenth century, took the emptiness to its logical extreme: not merely unoccupied but containing nothing at all. Together, the family illustrates how a single Latin concept — absence as a kind of freedom — scattered into English as property law, holiday planning, and physics.