volumetric displacement
noun
the volume of air per revolution that passes through a mechanical pump when the pressure at the intake and the exhaust is the same as that of the atmosphereAlso called: swept volume
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012