Science, Tech, Math › Science Vacuum Definition and Examples What Is a Vacuum? Share Flipboard Email Print This vacuum tube contains very low pressure inside the glass. luxxtek, Getty Images Science Chemistry Chemical Laws Basics Molecules Periodic Table Projects & Experiments Scientific Method Biochemistry Physical Chemistry Medical Chemistry Chemistry In Everyday Life Famous Chemists Activities for Kids Abbreviations & Acronyms Biology Physics Geology Astronomy Weather & Climate By Todd Helmenstine Todd Helmenstine is a science writer and illustrator who has taught physics and math at the college level. He holds bachelor's degrees in both physics and mathematics. our editorial process Todd Helmenstine Updated January 04, 2019 Vacuum Definition A vacuum is a volume that encloses little or no matter. In other words, it is a region that has a gaseous pressure much lower than that of atmospheric pressure.A partial vacuum is a vacuum with low amounts of matter enclosed. A total, perfect, or absolute vacuum has no matter enclosed. Sometimes this type of vacuum is referred to as "free space." The term vacuum comes from the Latin vacuus, which means empty. Vacuus, in turn, comes from the word vacare, which means "be empty." Common Misspellings vaccum, vaccuum, vacuume Vacuum Examples Vacuum tubes are devices, usually made of glass, that contain very low gas pressures inside the tube.Space is considered a vacuum. Space does contains matter, but the pressure is much lower than what you would find on a planet, for example.A vacuum cleaner sucks up debris because it creates a pressure difference between the area to be cleaned and the suction tube.Your lungs intake air when your diaphragm drops, creating a partial vacuum in the alveoli of the lungs, causing air to rush in.