vacuum

Etymology

From Latin vacuum (“an empty space, void”), noun use of neuter of vacuus (“empty”), related to vacare (“be empty”).

noun

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, colorless sulphur hexafluoride gas, held in place by carefully managed mass effect fields. 2008, BioWare, Mass Effect (Science Fiction), Redwood City: Electronic Arts, →OCLC, PC, scene: Citadel Station: Wards Codex entry
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. (colloquial, only pluralized as "vacuums") Ellipsis of vacuum cleaner.
4. (physics) A spacetime having tensors of zero magnitude.
5. An emptiness in life created by a loss of a person who was close, or of an occupation.
6. An exercise in which one draws their abdomen towards the spine.
   Abs show up in a most-muscular shot, a vacuum shot, the hands-behind-head compulsory ab shot, twisting poses, and so on. 1985, Arnold Schwarzenegger, Encyclopedia of Modern Bodybuilding, New York, N.Y.: Simon & Schuster, page 508
   Right I'm off to practice my vacuum - suck in those stomachs now! 1997-01-06, John, “I'm 14; How do I start bodybuilding?”, in misc.fitness.weights (Usenet)
   When I do the 'gut vacuum' exercise the abdominal wall seems to return to normal size, as far as I can tell under the flab. 2010-01-07, Silent Stone, “Want to start, have a few questions for now.”, in misc.fitness.weights (Usenet)
   Blessed with round muscle bellies and a phenomenal structure, he also performed a vacuum pose on stage. 2022-10-10, Aaromal Maanas, “2022 Tsunami Nutrition Pro Results and Recap”, in Sportskeeda, archived from the original on 2022-10-23

verb

1. (transitive) To clean (something) with a vacuum cleaner.
   “Who in the world cleans an attic? That's like vacuuming a shed.” 2016, Janice M. Whiteaker, Run
2. (intransitive) To use a vacuum cleaner.
3. (transitive, databases) To optimise a database or database table by physically removing deleted tuples.