go postal

present singular third person goes postal · participle present going postal · past went postal · participle past gone postal

1. USinformalintransitiveTo become aggressive and erratic, especially due to stress; specifically, to carry out a shooting spree at a workplace environment; also (more generally) to become very angry; to lose one's temper.

   1 more example

   Violence that spills in from the streets may be less worrisome than the worker rampages, to judge by the attentive audience of personnel managers (and the consultants available for hire) at "A Growing American Phenomenon: Workplace Violence." The symposium was sponsored by the U.S. Postal Service, which has seen so many outbursts that in some circles excessive stress is known as "going postal." Thirty-five people have been killed in 11 post office shootings since 1983.

   1993 December 17, Karl Vick, “Violence at work tied to loss of esteem”, in St. Petersburg Times, St. Petersburg, Fla.: The Times Publishing Co., →OCLC, page 4A, column 1

   Synonyms: run amok, crash out, Note: All terms are idiomatic unless stated otherwise., blow a fuse, blow a gasket, blow one's stack, blow one's top, crash out