A partial vacuum is a space that has less air or gas pressure compared to its surroundings. In simple terms, it means there is some empty space with less air or gas in it. Full definition
While calculating partial vacuum coefficient, ponder why air hockey is so much less violent than traditional hockey. (canadianbusiness.com)
The plastic pipes and the tubes with partial vacuums, the hydrometer and evaporator, storage tanks, and the bottles in which the product will be shipped - you need these components to keep your maple syrup business running. (netquote.com)
As the steam comes into contact with the product it creates a large dispersion zone and partial vacuum due to the Venturi effect. (oalgroup.com)