The word 'fiddle' can mean a type of musical instrument that is similar to a violin. It can also mean to play with something in a nervous or restless way.
You pronounce 'fiddle' like this: 'fid-ul'. The first part sounds like 'fid' and the second part sounds like 'ul'.
The word 'fiddle' comes from the Old English word 'fidel', which means a stringed instrument. It has been used for many years to describe instruments like the violin.