Definition of vacuum :
1. 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 inch.
senselessness, Hoover, mindlessness, void, vanity, desolation, pointlessness, nihility, blankness, emptiness, full, exhaustion, space, inanity, vacuum-clean, vacuity, barrenness, vacuum cleaner, rarefaction, nullity, nothingness, hollowness, vacancy
- Each tube when finished is exhausted, but not to a very high vacuum. - "Hertzian Wave Wireless Telegraphy", John Ambrose Fleming.
- Mabel, Duchess of Dachet, it is beginning to dawn upon the vacuum which represents my brain that I've been the victim of one of the prettiest things in practical jokes that ever yet was planned. - "Amusement Only", Richard Marsh.
- We know the comet's tail is so rarefied that it resembles a pretty fair vacuum, but it is composed of something. - "The Year When Stardust Fell", Raymond F. Jones.