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.
1. tr. clean with a vacuum cleaner.
2 intr. use a vacuum cleaner.
Phrases and idioms:
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