Definition of "suction"

suction

/ˈsʌkʃən/

noun
usually uncountable, plural suctions
1. (physics) A force which pushes matter from one space into another because the pressure inside the second space is lower than the pressure in the first.
2. (physics) A force holding two objects together because the pressure in the space between the items is lower than the pressure outside that space.
3. The process of creating an imbalance in pressure to draw matter from one place to another.
  Quotations
  The first-named group — the insects that live by suction — include the scale insects, aphides, and sucking bugs […]
  1901, “Progress in the Fruit Industry of Queensland”, in The Agricultural Journal and Mining Record‎, volume 4, page 16
4. (dentistry) A device for removing saliva from a patient's mouth during dental operations, a saliva ejector.
5. (informal) influence; "pull".
  Quotations
  He's got some kind of suction with the Mayor's office.
  2002 June 9, David Simon, “The Detail” (10:26 from the start), in The Wire, season 1, episode 2 (television production), spoken by Rhonda Pearlman (Deirdre Lovejoy), via HBO
verb
third-person singular simple present suctions, present participle suctioning, simple past and past participle suctioned
1. To create an imbalance in pressure between one space and another in order to draw matter between the spaces.
2. To draw out the contents of a space.