vacuum definition
(ËvÃ¦kjÊÉm) n, pl vacuums or vacua (ËvÃ¦kjÊÉ) 1. (General Physics) a region containing no matter; free space. Compare plenum3. 2. (General Physics) a region in which gas is present at a low pressure. 3. (General Physics) the degree of exhaustion of gas within an enclosed space: a high vacuum; a perfect vacuum.