vacuum servo
Also found in: Wikipedia.
vacuum servo
n
(Automotive Engineering) a servomechanism that is operated by the lowering of pressure in the intake duct of an internal-combustion engine
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014