pop one’s clogs

Definition

Slang

  • verb to die. A humorous, sometimes incongruously light-hearted phrase popular e.g. with TV presenters, disc jockeys and other entertainers. ‘Pop’ here is probably the old slang word for pawn, the suggestion being that when the family member dies, his or her clogs are sold.
http://www.dictionarycentral.com/definition/pop-one-s-clogs.html