Not occupied; empty, vacant, or unengaged with any work or activity.
From dis- + occupied. The dis- prefix negates the state of being occupied, creating an adjective meaning 'not occupied.'
While 'disoccupied' technically follows English word-formation rules, virtually no one uses it—'unoccupied' with the un- prefix is the standard choice. This shows how English learners sometimes use one prefix when another has become the conventional form.
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