Vacuum is space that is devoid o matter. The wird stems frae the Laitin adjective vacuus for "vacant" or "void". An approximation tae sic vacuum is a region wi a gaseous pressur much less nor atmospheric pressur. Pheesicists eften discuss ideal test results that wad occur in a perfect vacuum, which thay whiles simply caw "vacuum" or free space, an uise the term pairtial vacuum tae refer tae an actual imperfect vacuum as ane micht hae in a laboratory or in space. The Laitin term in vacuo is uised tae describe an object as bein in whit wad itherwise be a vacuum.