The Fat Vac is the slang term for the machine used to perform liposuction. Fat Vac is the abbreviation of Fat Vacuum. It has the same meaning as Vacuumed
This term was popularized by the TV show Scrubs when Jordan shouts out "Fire up the fat vac!" referring to Liposuction.
Jordan: Fire up the fat vac! Mama Needs some Lipo.
Sophie: Wheres Carla?
Lindsay: The Lipette's back at the fat vac