Here are some examples of words with the prefix "vac":
* Vacant: Empty, not occupied
* Vacation: A period of time away from work or school
* Vacate: To leave a place, especially to make it empty
* Vacuum: A space entirely devoid of matter
* Vacuous: Lacking in intelligence or meaning
It's important to note that "vac" can sometimes be a shortened form of "vaccin-", derived from the Latin "vacca" meaning "cow." This is used in words like vaccine and vaccination.