Is it ensure, insure, or assure?
1540s, "emptiness of space," from Latin vacuum "an empty space, void," noun use of neuter of vacuus "empty," related to vacare "be empty" (see vain). Properly a loan-translation of Greek kenon, literally "that which is empty." Meaning "a place emptied of air" is attested from 1650s. Vacuum tube is attested from 1859. Vacuum cleaner is from 1903; shortened form vacuum (n.) first recorded 1910.
"to clean with a vacuum cleaner," 1922; see vacuum (n.). Related: Vacuumed; vacuuming.
vacuum vac·u·um (vāk'yōō-əm, -yōōm, -yəm)
n. pl. vac·u·ums or vac·u·a (-yōō-ə)
Absence of matter.
A space empty of matter.
A space relatively empty of matter.
A space in which the pressure is significantly lower than atmospheric pressure.
Plural vacuums or vacuua
The absence of matter.
Note: In the natural world, air will flow into regions of vacuum, giving rise to the saying “Nature abhors a vacuum.”
Note: The saying is extended informally: in politics, a lack of leadership may be referred to as a vacuum, which will presumably be filled by others rushing in.