Something that has been left in the toaster, such as a bagel, poptart, or (especially) toast. It was cooked, likely for the intent of eating, but was neglected for days for whatever reason. This is usually performed by siblings who have plenty of time to eat it, or parents, who keep their coffee in the microwave for days without drinking it. This could technically be considered toasterbread too.
Hey, who's toast is this? It's getting cold, dont you want it? (one week later) Nobody ate the toast... now it's toasterbread. -_-
When some resigns or retires from a job, they are on "eternity leave". This can also refer to someone who has passed away, especially someone who worked somewhere for a long time, retired/resigned, then passed away later.
Oh I'm sorry, you didn't know that Kelly is on eternity leave? She resigned and moved to Hawaii!
With regrets I would like to inform you that my boss is officially on eternity leave. I will never see or hear them again. Ever.