This word can be found scrawled onto Sam Endicott's (of The Bravery) knuckles.
Over time, The Spice Girls somewhat unfortunately became lionized. Thankfully those who did this finally woke up and plunged The Spice Girls into a pit of global hatred. Justice has been served.
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.