vacuum

• POS: Noun, Verb (usu participle)
• HYPHEN: vac=u=um

CIDE DICTIONARY

vacuum, n. [L., fr. vacuus empty. See Vacuous.].

•  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.  [1913 Webster]
•  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 inch.  [1913 Webster]

Vacuum 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.

OXFORD DICTIONARY

vacuum, n. & v.
--n. (pl. vacuums or vacua)
1 a space entirely devoid of matter.
2 a space or vessel from which the air has been completely or partly removed by a pump etc.
3 a the absence of the normal or previous content of a place, environment, etc. b the absence of former circumstances, activities, etc.
4 (pl. vacuums) colloq. a vacuum cleaner.
5 a decrease of pressure below the normal atmospheric value.
--v. colloq.
1 tr. clean with a vacuum cleaner.
2 intr. use a vacuum cleaner.

Idiom

vacuum brake a brake in which pressure is caused by the exhaustion of air. vacuum-clean clean with a vacuum cleaner. vacuum cleaner an apparatus for removing dust etc. by suction. vacuum flask Brit. a vessel with a double wall enclosing a vacuum so that the liquid in the inner receptacle retains its temperature. vacuum gauge a gauge for testing the pressure after the production of a vacuum. vacuum-packed sealed after the partial removal of air. vacuum pump a pump for producing a vacuum. vacuum tube a tube with a near-vacuum for the free passage of electric current.

Etymology

mod.L, neut. of L vacuus empty

THESAURUS

vacuum

absence, absence of mind, blank, blankness, broom, brush, brush off, clean slate, deprivation, emptiness, empty space, empty-headedness, hollowness, inanity, jejunity, mental void, negation, negativeness, negativity, nihility, nonbeing, nonentity, nonexistence, nonoccurrence, nonreality, nonsubsistence, not-being, nothing, nothingness, nullity, sweep, sweep out, sweep up, tabula rasa, unactuality, unreality, vacancy, vacuity, vacuousness, vacuum-clean, vapidity, void, whisk

ROGET THESAURUS

vacuum

Absence

N absence, inexistence, nonresidence, absenteeism, nonattendance, alibi, emptiness, void, vacuum, vacuity, vacancy, tabula rasa, exemption, hiatus, lipotype, truant, absentee, nobody, nobody present, nobody on earth, not a soul, ame qui vive, absent, not present, away, nonresident, gone, from home, missing, lost, wanting, omitted, nowhere to be found, inexistence, empty, void, vacant, vacuous, untenanted, unoccupied, uninhabited, tenantless, barren, sterile, desert, deserted, devoid, uninhabitable, without, minus, nowhere, elsewhere, neither here nor there, in default of, sans, behind one's back, the bird has flown, non est inventus, absence makes the heart grow fonder, absent in body but present in spirit, absento nemo ne nocuisse velit, Achilles absent was Achilles still, aux absents les os, briller par son absence, conspicuous by his absence, in the hope to meet shortly again and make our abs.

Gaseity

N gaseity, vaporousness, flatulence, flatulency, volatility, aeration, aerification, elastic fluid, gas, air, vapor, ether, steam, essence, fume, reek, effluvium, flatus, cloud, ammonia, ammoniacal gas, volatile alkali, vacuum, partial vacuum, pneumatics, pneumatostatics, aerostatics, aerodynamics, gasmeter, gasometer, air bladder, swimming bladder, sound, (of a fish), gaseous, aeriform, ethereal, aerial, airy, vaporous, volatile, evaporable, flatulent.