[duhb-uh l-ak-ting]
  1. (of a reciprocating engine, pump, etc.) having pistons accomplishing work in both directions, fluid being admitted alternately to opposite ends of the cylinders.Compare single-acting.
  2. (of a hinge of a door or the like) permitting movement in either direction from the normal, or closed, position.
  3. having twice the usual effectiveness, strength, use, etc.

Origin of double-acting

First recorded in 1835–45 Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for double-acting

Historical Examples of double-acting

British Dictionary definitions for double-acting


  1. (of a reciprocating engine or pump) having a piston or pistons that are pressurized alternately on opposite sidesCompare single-acting
  2. (of a hinge, door, etc) having complementary actions in opposed directions
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