E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
The Roman wall between the friths of the Clyde and Forth, so called from the first person who leaped over it after the Romans left Britain.
This wall defended the Britons for a time, but the Scots and Picts assembled themselves in great numbers, and climbed over it . A man named Grahame is said to have been the first soldier who got over, and the common people still call the remains of the wall Grahames Dike.Sir Walter Scott: Tales of a Grandfather.