vacuüm

Noun

vacuum (plural vacuums or (rare, formal, see notes) vacua)

1. A region of space that contains no matter.
   • The Wards are open-topped, with skyscrapers rising from the superstructure. Towers are sealed against vacuum, as the breathable atmosphere envelope is only maintained to a height of about seven meters. The atmosphere is contained by the centrifugal force of rotation and a "membrane" of dense...2008, BioWare, Mass Effect (Science Fiction), Redwood City: Electronic Arts, →ISBN, →OCLC, PC, scene: Citadel Station: Wards Codex entry

   Synonyms:

   vacancy, void

   Antonyms:

   plenum

2. 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
3. A spacetime having tensors of zero magnitude.
4. A ground state of a quantum field or of local spacetime, or more abstractly the lowest-energy state of a system.
   1. (string theory) A description of spacetime resulting from a particular compactification of spatial dimensions.
5. An emptiness in life created by a loss of a person who was close, or of an occupation.
   • Henrietta soon found a terrible vacuum left, by the letters in which she used to pour forth every feeling and thought to her uncle.1837, L[etitia] E[lizabeth] L[andon], Ethel Churchill: Or, The Two Brides. […], volume III, London: Henry Colburn, […], →OCLC, pages 82–83

See all 10 meanings of vacuum