suction

n. act of sucking; force which attracts a substance or object into a partial or complete vacuum

Suction is the creation of a partial vacuum, or region of low pressure. The pressure gradient between this region and the ambient pressure will propel matter toward the low pressure area. Physicists consider the notion of "suction" to be specious, since vacuums do not innately attract matter. Dust being "sucked" into a vacuum cleaner is actually being pushed in by the higher pressure air on the outside of the cleaner.
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Suction /suc·tion/ aspiration of gas or fluid by mechanical means. post-tussive suction a sucking sound heard over a lung cavity just after a [more]Suction - Community and Resources

Noun
1. a force over an area produced by a pressure difference
(hypernym) pressure, pressure level, force per unit area
2. the act of sucking
(synonym) sucking, suck
(hypernym) consumption, ingestion, intake, uptake
Verb
1. remove or draw away by the force of suction; "the doctors had to suction the water from the patient's lungs"
(derivation) sucking, suck
2. empty or clean (a body cavity) by the force of suction; "suction the uterus in an abortion"
(hypernym) evacuate, void, empty
(derivation) sucking, suck
(classification) operation, surgery, surgical operation, surgical procedure, surgical process

(v. t.)
The act or process of sucking; the act of drawing, as fluids, by exhausting the air.