Vacuum

noun, plural vacuums for 1, 2, 4–6, vacua
[vak-yoo-uh] /ˈvæk yu ə/ (Show IPA), for 1, 2, 4, 6.
1.
a space entirely devoid of matter.
2.
an enclosed space from which matter, especially air, has been partially removed so that the matter or gas remaining in the space exerts less pressure than the atmosphere (opposed to plenum).
3.
the state or degree of exhaustion in such an enclosed space.
4.
a space not filled or occupied; emptiness; void:
The loss left a vacuum in his heart.
5.
a vacuum cleaner or sweeper.
6.
Physics. a state of lowest energy in a quantum field theory.
adjective
7.
of, pertaining to, employing, or producing a vacuum.
8.
(of a hollow container) partly exhausted of gas or air.
9.
pertaining to a device or process that makes use of a vacuum to accomplish a desired task.
10.
noting or pertaining to canning or packaging in which air is removed from the container to prevent deterioration of the contents.
verb (used with object)
11.
to use a vacuum cleaner on; clean with a vacuum cleaner:
to vacuum rugs.
12.
to treat with any vacuum device, as a vacuum drier.
verb (used without object)
13.
to use a vacuum cleaner:
to vacuum in the dining room.
noun (pl) vacuums, vacua (ˈvækjʊə)
1.
a region containing no matter; free space Compare plenum (sense 3)
2.
a region in which gas is present at a low pressure
3.
the degree of exhaustion of gas within an enclosed space: a high vacuum, a perfect vacuum
4.
a sense or feeling of emptiness: his death left a vacuum in her life
5.
short for vacuum cleaner
6.
(modifier) of, containing, measuring, producing, or operated by a low gas pressure: a vacuum tube, a vacuum brake
verb
7.
to clean (something) with a vacuum cleaner: to vacuum a carpet

vacuum vac·u·um (vāk’yōō-əm, -yōōm, -yəm)
n. pl. vac·u·ums or vac·u·a (-yōō-ə)

Absence of matter.

A space empty of matter.

A space relatively empty of matter.

A space in which the pressure is significantly lower than atmospheric pressure.

vacuum
(vāk’ym)
Plural vacuums or vacuua

A region of space in which there is no matter.

A region of space having extremely low gas pressure relative to surrounding pressure. The air pump of a vacuum cleaner, for example, drastically reduces the air pressure inside the device, creating a vacuum; the pressure difference causes air to rush into it, carrying dust and debris along with it.

vacuum definition

The absence of matter.

Note: In the natural world, air will flow into regions of vacuum, giving rise to the saying “Nature abhors a vacuum.”

Note: The saying is extended informally: in politics, a lack of leadership may be referred to as a vacuum, which will presumably be filled by others rushing in.