It's a 'polite' version of The Bloody Tower, which is part of The Tower of London.

Weston and Lee also wrote "With her head tucked underneath her arm" in which Anne Boleyn "walks the Bloody Tower". Reportedly, the BBC were happy to hear it sung with a northern accent, but got hot under the collar when it was sung in a Cockney accent because it sounded like the swearing they heard in the London streets. So 'Adjective' is an in-joke by the writers.

Georgina