Glass Onion

Originating from the Beatles song "Glass Onion" off their 1968 self-titled, or "white" album, the term was believed to mean a glass-lidded coffin by the followers of the Paul is Dead conspiracy. The real meaning of the song is that people were over-analyzing the Beatles' lyrics. A glass onion is something that would have layer after layer peeled away, only to realise that it was transparent all along.