A place which is empty.  The term is principally applied to cases where the office is not filled.  As applied to an office, it has no technical meaning; People v. Edwards, 93 cal. 153, 28 Pac. 831; State v. Bemenderfer, 96 Ind. 374.

By the constitution of the United States, the president has the power to fill vacancies that may happen during the recess of the senate.  See Tenure of Office; Officer; Resignation.

Source: Bovier’s Law Dictionary & Concise Encyclopedia, 3rd Revision