Green’s Dictionary of Slang

chatham and dover v.

to stop, to cease.

1909

J. Ware Passing Eng. of the Victorian Era 71/1: Chatham and Dover (London public house rhyming). ‘Over.’ This phrase is generally used as a pacificating one – in a tavern quarrel, a friend will say, ‘Come – Chatham and Dover it’ – meaning give it over.