Tomfoolery

Tomfoolery meaning silly or foolish behaviour dates from the early 19th century. Tom Fool as an expression for a fool has been known since the 14th century when Tom, as a common name, was used to personify stereotypes. Thus, Tom Long would be someone exceptionally tall, Tom Piper would play the pipes, and Tom Fool would be the village idiot. Tomfoolery is also rhyming slang for jewellery, tomfoolery/jewellery, and dates from the late 19th century.