vacuum

¹vac·u·um

noun \ˈvak-(ˌ)yüm, -yu̇-əm, -yəm\

plural vac·u·ums or vac·ua \-yə-wə\

Definition of VACUUM

1

: emptiness of space

2

a : a space absolutely devoid of matter b : a space partially exhausted (as to the highest degree possible) by artificial means (as an air pump) c : a degree of rarefaction below atmospheric pressure : negative pressure