Fiddle-de-dee is a phrase that originated in the United States in the early 19th century. It is used to express JOY or excitement, and is often used in folk songs and other traditional music. The term is usually used with the three letter word 'dee, ' which is derived from the Middle English word for 'JOY.' Fiddle-de-dee is often used as a call and response between two people, with one person saying 'fiddle-de-dee' and the other responding with 'dee.'