suction

noun

1. (uncountable, usually)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. (uncountable, usually)A force holding two objects together because the pressure in the space between the items is lower than the pressure outside that space.
3. (uncountable, usually)The process of creating an imbalance in pressure to draw matter from one place to another.

   “The first-named group — the insects that live by suction — include the scale insects, aphides, and sucking bugs[…]”

4. (uncountable, usually)A device for removing saliva from a patient's mouth during dental operations, a saliva ejector.
5. (informal, uncountable, usually)influence; "pull".

   “He's got some kind of suction with the Mayor's office.”

verb

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.