Main Entry: ¹vac·u·um

Pronunciation: \ˈvak-(ˌ)yüm, -yu̇-əm, -yəm\

Function: noun

Inflected Form(s): plural vac·u·ums or vac·ua \-yə-wə\

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