Wordology, Old Chestnut

An 'old chestnut' is another way of saying a joke is old or stale. The origin appears to be eating roasted chestnuts at the fireside while listening to old stories.

The Broken Sword, was a melodrama by William Dimond (1816) in which one of the characters, Captain Xavier, is forever telling the same jokes, over and over, with slight variations. As he repeats a certain joke involving a cork tree, he is corrected. The man says, "A chestnut. I have heard you tell the joke twenty-seven times, and I am sure it was a chestnut."