/ Dictionary / Index W water jacket: Meaning and Definition of Find definitions for: wa'ter jack"et Pronunciation: [key] a water-filled casing or compartment used to water-cool something, as an engine or machine gun. wa•ter-jack•et Pronunciation: (wô'tur-jak"it, wot'ur-), [key] — v.t. to surround or fit with a water jacket. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. waterish waterjet Related Content Daily Word Quiz: fresco Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language