You can make emergency plans: bring your helmet and flak jacket, get to high ground, or get out of Dodge.
He was bare armed under a protective jacket a jail official termed “a kind of flak jacket.”
Why wasn't he asking me what I, a white girl with a flak jacket, was doing crossing into Syria?
A bulletproof vest or other protective garment for the chest: the flak jacket Oiler QB Dan Pastorini wore last year/ Nebraska officials said that Berringer, who was wearing a flak jacket, was not in pain but was held out in the second half
[1950s+; fr the protective jacket worn by aircrew members in WWII]