Definitions
1.nounA region of space that contains no matter.
2.noun(plural only "vacuums") A vacuum cleaner.
3.nounThe 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"
4.nounA spacetime having tensors of zero magnitude
5.verbTo clean (something) with a vacuum cleaner.
6.verbTo use a vacuum cleaner.
7.verbTo optimise a database or database table by physically removing deleted tuples.