This is
slang that originated with American soldiers during World
War II. Many US troops were armed with their fully automatic equivalent of the STEN
gun, the M3 submachine
gun which, because of its resemblance to the mechanic’s tool was called the ‘grease
gun’. With the slightly macabre humour prevalent amongst those who are in combat, enemy troops killed by this weapon were referred to as having been ‘greased’.
It quickly came to mean killed by multiple bullet wounds from any type of machine
gun. It was during the Vietnam
War, however, that its use expanded and increased quite dramatically until it became used to describe any death in action against the enemy.
There is now some evidence to suggest that the word greased is being used to describe any violent death, even where this is not in combat and when it
may even be an accident.
