- A region of space that contains no matter.
- The condition of rarefaction, or reduction of pressure below that of the atmosphere, in a vessel, such as the condenser of a steam engine, which is nearly exhausted of air or steam, etc.
"a vacuum of 26 inches of mercury, or 13 pounds per square inch"
- A vacuum cleaner.
- (transitive) To clean (something) with a vacuum cleaner.
- (intransitive) To use a vacuum cleaner.