Refers to a person who has not had sex for a while. Often resulting in over masturbation and a flacid penis. If the individual persits in not getting laid symptoms can progress to homoeroticism, wrist cramps and desperation. (that may lead to sex with becca ahhhhh!!)
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.