E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Cicerone (4 syl.).
A guide to point out objects of interest to strangers. So called in the same way as Paul was called by the men of Lystra Mercurius, because he was the chief speaker (Acts xiv. 12). Cicero was the speaker of speakers at Rome; and certainly, in a party of sight-seers, the guide is the chief speaker. It is no compliment to the great orator to call the glib patterer of a show-place a Cicero; but we must not throw stones at our Italian neighbours, as we have conferred similar honour on our great epic poet in changing Grub Street into Milton Street.
Every glib and loquacious hireling who shows strangers about their pleasure-galleries, palaces, and ruins is called [in Italy] a cicerone or a Cicero.Trench: On the Study of Words, lecture iii. p. 88.