Definition of: vacuum

(vak′y·əm, -ym) noun plural ·u·ums or ·u·a (-y·ə)
1. Physics a A space absolutely devoid of matter, b A space from which air or other gas has been exhausted to a very high degree.
2. A partial diminution of the normal atmospheric pressure.
3. A void; an empty feeling.
—adjective
1. Of, or used in the production of, a vacuum.
2. Exhausted or partly exhausted of gas, air, or vapor.
3. Operated by suction to produce a vacuum.
—v.t. & v.i. Colloq. To clean with a vacuum cleaner. [<L, neut. of vacuus empty]