Roaring Meg

Noun

 * 1) A large cannon; specifically, the large 15th cannon at  (more usually called ‘Mons Meg’), or the cannon used to defend [London]derry during the siege of 1688-9.
 * 2)  Any large or impressive thing.
 * 3)  A kind of spinning top.
 * 1)  A kind of spinning top.