To eighty-six something is to cancel it, reject it, or prevent it from coming to fruition, and to eighty-six a person is to eject them, especially from a business premises, or to remove them from a role. For example, a picnic might be eighty-sixed because of rain, an injured player might be eighty-sixed from tomorrow’s game, and a misbehaving child might have her TV time eighty-sixed.
Meanwhile, the verb still appears in its two older senses, which come from mid-20th-century restaurant lingo: (1) to take an item off the menu because it has run out, and (2) to refuse service (to someone). For instance, when a beer on tap runs out, it is eighty-sixed, and when a drunk bar patron gets in a fight, he or she might be eighty-sixed for good.
In its even older sense—originally from the 1930s, according to the OED—the word is a noun denoting (1) something that a restaurant or bar has run out of, or (2) a customer who is no longer to be served. The word is now rarely used this way.
There is little doubt that eighty-six was originally U.S. restaurant and bar lingo, but its exact derivation is not known. Theories abound, but none are especially plausible (though everyone seems to like the theory that eighty-six is rhyming slang for nix). Detailed summaries of some of these theories are easily found elsewhere on the web.
Spelled out, the word is inflected eighty-sixed and eighty-sixing. It is sometimes written 86, though, in which case it’s usually inflected with an apostrophe: 86′d and 86′ing.
And there seems to be a recurring theme among mullet wearers — outside pressure from friends and family to eighty-six it. [Pittsburgh Post Gazette]
[B]e sure that all of the staff and management are aware of the circumstances and the identity of the eighty-sixed former patron. [The Bartender's Best Friend, Mardee Haidin Regan]
Sandwich voters eighty-six extra meals tax [Cape Cod Times]
The tweets have since been removed, but a big thanks to Bleeding Cool for nabbing them before they were 86′d. [Dread Central]
John Hawkes, however, was the last person anyone might have suspected would get eighty-sixed from the Oscar proceedings. [Word & Film]
Annoyed, he moved to eighty-six her. In response, Jesse made a hands-up gesture of surrender but retreated only a few steps. [Freedomland, Richard Price]