go postal 

To lash out violently and at random, often in a blind rage. Term taken from the 1990's incidents of workplace violence involving US Postal System workers.

I was so angry at work with the new workload, I was afraid I'd go postal.

go postal by Unidyne March 11, 2005

go postal 

To exact calculated revenge on co-workers or schoolmates, usually with a firearm, after being fired or expelled or just feeling extremely hard-done-by.

Software tester Michael McDermott shot and killed seven co-workers in 2000 after having his pay docked to cover back taxes.

A disgruntled former worker went postal today leaving seven dead, including two accountants he had accused of being 'Nazis' the day before.

go postal by bee May 13, 2005

go postal 

to succumb to fatigue and tension, to be become violently angry(from a series of incidents from the mid 80s to the 90s where various postal workers went on shooting rampages)

I will not let him go postal in plain sight.

go postal by The Return of Light Joker July 1, 2008

Go postal 

To go apeshit with pure hatred and blind anger, termed after workplace shootings perputrated by postal service / mail service employees. Going postal involves taking a firearm to place of work or anywhere and just unloading into everything in sight.

*gunfire in workplace*
*secetary bolts through office door*
Secretary : "TERRY'S FINALLY DONE IT, HE'S DECIDED TO Go Postal!"
*screams in hall outside door as boots stomp down hall*
Boss : "shit lol"

Go postal by grandest of autismo April 22, 2021

go postal 

To loose touch with someone for a long time. Not talk to someone in a while.

You go postal on me all the time and I only hear from you every 3 months.

go postal by Boopboop June 25, 2007