# vacuum

Pronunciation: say "VA-kyoom" /ˈvæ.kjuːm/

## Noun

1. A region of space empty of all matter.
   - Simple: An empty space with nothing in it at all: no air and no other matter.
   - _Without air resistance, a feather and a hammer fall at the same rate in a vacuum._
   - _The bell jar created a near vacuum around the ringing alarm._
2. Shortened form of vacuum cleaner. *(colloquial)* — Ellipsis of vacuum cleaner.
   - Simple: Shortened form of vacuum cleaner. A casual, everyday way to name the machine that sucks up dirt.
   - _She dragged the vacuum up the stairs to clean the bedrooms._
   - _Our new vacuum barely makes any noise._
5. An emptiness in one's life left by the loss of a close person or of an occupation.
   - Simple: A sad, empty feeling left when you lose someone close or lose your job.
   - _The founder's departure left a vacuum at the top of the company._
   - _After the children moved out, she felt a strange vacuum in her days._
6. A reduction of pressure inside a vessel to well below that of the surrounding atmosphere, as in the condenser of a steam engine.
   - Simple: A space inside a container where the air pressure is much lower than the air around us.
   - _The condenser maintains a partial vacuum to improve the engine's efficiency._
   - _Operators measured the vacuum in the vessel with a gauge._
7. An abdominal exercise in which one draws the belly inward toward the spine and holds the contraction.
   - Simple: A belly exercise where you pull your stomach in toward your spine and hold it.
   - _He added the vacuum to his routine to train his deep abdominal muscles._
   - _Hold the vacuum while breathing slowly to engage the transverse abdominals._
8. A region of spacetime whose tensors have zero magnitude, describing space free of matter and energy.
   - Simple: In physics, a model of empty spacetime that holds no matter and no energy.
   - _The Schwarzschild solution describes the vacuum surrounding a non-rotating mass._
   - _Gravitational waves can travel through a vacuum where no matter exists._

## Verb

3. To clean something by going over it with a vacuum cleaner.
   - Simple: To clean a floor or surface using a machine that sucks up dirt.
   - _Volunteers vacuum the hall after every event._
   - _He vacuumed the car seats to get rid of the sand._
4. To do household cleaning by operating a vacuum cleaner.
   - Simple: To clean a room by running a machine that sucks up dirt.
   - _They vacuum all over the house on weekends._
   - _He vacuums while listening to music._
9. In databases, to optimize a table by physically removing rows that were previously deleted.
   - Simple: In computing, to clean up a database by removing data that was already marked for deletion.
   - _Engineers vacuum large tables regularly to reclaim disk space._
   - _The maintenance job vacuumed the orders table overnight._

## Origin

Borrowed from New Latin vacuum ("vacuum"), a sense of Classical Latin vacuum ("empty space"), which was a noun form of vacuus ("empty"); it is related to vacāre ("to be empty").

Source: DictionaryAI, https://dictionaryai.com/define/vacuum (written from Wiktionary data, CC BY-SA 4.0: https://creativecommons.org/licenses/by-sa/4.0/).