[waw-ter-jak-it, wot-er-]

verb (used with object)

to surround or fit with a water jacket.

Origin of water-jacket

First recorded in 1875–80

water jacket


a water-filled casing or compartment used to water-cool something, as an engine or machine gun.

Origin of water jacket

First recorded in 1865–70
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for water-jacket

Historical Examples of water-jacket

  • Fixed: a barrel-casing, which is also a water-jacket, and breech-casing.

  • A double cylinder formed a water-jacket, connected with a water and steam chamber above, and a water-chamber below.

    Automobile Biographies

    Lyman Horace Weeks

  • The loss of heat through the water-jacket is thus less in the case of a high-compression than in that of a low-compression motor.

    Aviation Engines

    Victor Wilfred Pag

  • It does not heat fast, so has no need of a water-jacket, any surplus heat being removed by a system of radiation.

  • He pulled the Maxim's block and threw it away; shot the water-jacket full of holes.


    Edward Elmer Smith

British Dictionary definitions for water-jacket

water jacket


a water-filled envelope or container surrounding a machine, engine, or part for cooling purposes, esp the casing around the cylinder block of a pump or internal-combustion engineCompare air jacket
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