(US) A day when one is permitted to not attend work in order to go on a vacation or attend to other matters.

plural of vacance

(chemistry) Distillation under reduced pressure, and thus at a reduced temperature with less risk of thermal degradation

Emptiness.

plural of vacuum pump

(medicine) An infection of cowpox. / (by extension) The virus which causes this infection.

plural of vacuum flask

An area that is often the site of vacations, or well suited for vacations.

plural of vacationland

A polio vaccine that is taken by mouth, and contains the three serotypes of polio in a weakened live state.