an enclosed space from which matter, esp. 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.
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.
[vak-yoom, -yoo-uh
m, -yuh
noun, plural vac⋅u⋅ums for 1, 2, 4–6, vac⋅u⋅a 
m) Pronunciation Key
