noun
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.
(colloquial, only pluralized as "vacuums") Ellipsis of vacuum cleaner.
(physics) A spacetime having tensors of zero magnitude.
(physics) A ground state of a quantum field or of local spacetime, or more abstractly the lowest-energy state of a system.
An emptiness in life created by a loss of a person who was close, or of an occupation.
An exercise in which one draws their abdomen towards the spine.
verb
(transitive) To clean (something) with a vacuum cleaner.
(intransitive) To use a vacuum cleaner.
(transitive, databases) To optimise a database or database table by physically removing deleted tuples.