postal
adj. C1 Advanced US //ˈpoʊstəɫ// UK //pˈəʊstəl// postal
adj. becoming extremely and uncontrollably angry, often in a violent way. You use this to describe someone who suddenly loses their temper completely.
adj. becoming suddenly and uncontrollably angry or violent, particularly in a workplace or public setting. Often used in the phrase 'to go postal', it carries a highly informal and potentially insensitive register due to its origins in workplace shootings.
He went postal when he saw the damage to his car.
The manager was afraid that if he fired the employee without a witness, the man might go postal.
From post + -al, modelled on French postal.
Usage
Almost exclusively used in the predicative position following the verb 'go'.