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.
1550, "emptiness of space," from L. vacuum "an empty space, void," noun use of neuter of vacuus "empty," related to vacare "be empty" (see vain). Properly a loan-translation of Gk. xenon, lit. "that which is empty." Meaning "a place emptied of air" is attested from 1652. Vacuum tube is attested from 1859. Vacuum cleaner is from 1903; shortened form vacuum (n.) first recorded 1910. The verb meaning "to clean with a vacuum cleaner" is recorded from 1922.
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.
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.
Pan\, n. [OE. panne, AS. panne; cf. D. pan, G. pfanne, OHG. pfanna, Icel., Sw., LL., & Ir. panna, of uncertain origin; cf. L. patina, E. paten.]1. A shallow, open dish or vessel, usually of metal, employed for many domestic uses, as for setting milk for cream, for frying or baking food, etc.; also employed for various uses in manufacturing. "A bowl or a pan." --Chaucer. 2. (Manuf.) A closed vessel for boiling or evaporating. See Vacuum pan, under Vacuum. 3. The part of a flintlock which holds the priming. 4. The skull, considered as a vessel containing the brain; the upper part of the head; the brainpan; the cranium. --Chaucer. 5. (C?rp.) A recess, or bed, for the leaf of a hinge. 6. The hard stratum of earth that lies below the soil. See Hard pan, under Hard. 7. A natural basin, containing salt or fresh water, or mud. Flash in the pan. See under Flash. To savor of the pan, to suggest the process of cooking or burning; in a theological sense, to be heretical. --Ridley. Southey.
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