E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
A public-house sign. The Mirror says: In 1739, after the capture of Portobello, Admiral Vernons portrait dangled from every sign-post, and he may figuratively be said to have sold the ale, beer, porter, and purl of England for six years. The Portobello Arms is a mere substitution for the admiral.