Definify.com
Webster 1913 Edition
Vacuum
Vac′u-um
(văk′ū̍-ŭm)
, Noun.
pl. E.
Vacuums
(văk′ū̍-ŭmz)
, L. Vacua
(văk′ū̍-ȧ)
. [L., fr.
vacuus
empty. See Vacuous
.] 1.
(Physics)
A space entirely devoid of matter (called also, by way of distinction, absolute vacuum); hence, in a more general sense, a space, as the interior of a closed vessel, which has been exhausted to a high or the highest degree by an air pump or other artificial means;
as, water boils at a reduced temperature in a
. vacuum
2.
The condition of rarefaction, or reduction of pressure below that of the atmosphere, in a vessel, as the condenser of a steam engine, which is nearly exhausted of air or steam, etc.;
as, a
. vacuum
of 26 inches of mercury, or 13 pounds per square inchVacuum brake
, a kind of continuous brake operated by exhausting the air from some appliance under each car, and so causing the pressure of the atmosphere to apply the brakes.
– Vacuum pan
(Technol.)
, a kind of large closed metallic retort used in sugar making for boiling down sirup. It is so connected with an exhausting apparatus that a partial vacuum is formed within. This allows the evaporation and concentration to take place at a lower atmospheric pressure and hence also at a lower temperature, which largely obviates the danger of burning the sugar, and shortens the process.
– Vacuum pump
. Same as
– Pulsometer
, 1. Vacuum tube
(Phys.)
, (a)
a glass tube provided with platinum electrodes and exhausted, for the passage of the electrical discharge; a Geissler tube.
(a)
any tube used in electronic devices, containing a vacuum and used to control the flow of electrons in a circuit, as a vacuum diode, triode, tetrode, or pentode.
– Vacuum valve
, a safety valve opening inward to admit air to a vessel in which the pressure is less than that of the atmosphere, in order to prevent collapse.
– Torricellian vacuum
. See under
Torricellian
.Webster 1828 Edition
Vacuum
VAC'UUM
,Noun.
Torricellian vacuum, the vacuum produced by filling a tube with mercury, and allowing it to descend till it is counterbalanced by the weight of the atmosphere, as in the barometer invented by Torricelli.
Definition 2024
vacuum
vacuum
See also: vacuüm
English
Alternative forms
- vacuüm (rare)
Noun
vacuum (plural vacuums or vacua) (see usage notes)
- A region of space that contains no matter.
- (plural only "vacuums") A vacuum cleaner.
- The condition of rarefaction, or reduction of pressure below that of the atmosphere, in a vessel, such as the condenser of a steam engine, which is nearly exhausted of air or steam, etc.
- a vacuum of 26 inches of mercury, or 13 pounds per square inch
Usage notes
- The Latin in vacuo is sometimes used instead of in a vacuum (in free space).
Synonyms
- (vacuum cleaner): hoover (British)
Antonyms
- (region of space that contains no matter): plenum
Derived terms
Terms derived from vacuum
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Related terms
Related terms
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Translations
region of space that contains no matter
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vacuum cleaner — see vacuum cleaner
Verb
vacuum (third-person singular simple present vacuums, present participle vacuuming, simple past and past participle vacuumed)
- (transitive) To clean (something) with a vacuum cleaner.
- (intransitive) To use a vacuum cleaner.
- (transitive, databases) To optimise a database or database table by physically removing deleted tuples.
Synonyms
- (transitive sense): to hoover (British)
- (intransitive sense): to do the hoovering, to hoover (British)
Translations
transitive: to clean with a vacuum cleaner
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intransitive: to use a vacuum cleaner
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