Irish goodbye

[Becky]

In Germany we call this since a long time a French Goodbye! With the exception that this person forgot to pay his bill.

[Rihanna]

Leaving quietly out the side door of a party or bar without saying goodbye to anyone. Mostly due to the fact that family or friends would most likely take your keys away for being to intoxicated.

[Little_Girl]

When two leprichauns slap their cocks together on departing

[Tanya Shivari]

To depart, as from a bar or pub, without notifying the friends or family you are with.

[Rihanna]

When you leave any social enviroment without telling anyone.

[Sonia]

A goodbye taking more than 1 hour and in which a new conversation begins. People can spend hours on end standing in the driveway talking, during an Irish Goodbye. Not limited to Irish people, but very common among large Irish Families.
This type of goodbye is different because the more serious one is about leaving, the longer they stay around for.

[Tina]

When someone makes an [exit] without [advance] notice or saying [goodbye] - thus avoiding any displaying any emotion.

[Kai]

The act of leaving a social [gathering] suddenly, and without [any word] of [goodbye] to the other attendees.