flak jacket

American

noun

U.S. Air Force. an armored garment made of steel plates covered by a padded fabric, designed to protect vital parts of the body from shrapnel.
a protective vest, especially one that is bulletproof.

flak jacket British

noun

a reinforced sleeveless jacket for protection against gunfire or shrapnel worn by soldiers, policemen, etc

"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

Etymology

Origin of flak jacket

First recorded in 1955–60

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023