The phrase before you can say Jack Robinson means very quickly, in no time at all. But who was Jack Robinson and how did his name become associated with speed? The answer is we don’t really know, but there are many different explanations.
We do know that the phrase dates to at least 1778 when it appears in Fanny Burney’s Evelina:
I’d do it as soon as say Jack Robinson.
Grose’s 1785 Classical Dictionary of the Vulgar Tongue glosses it as:
Before one could say Jack Robinson; a saying to express a very short time, originating from a very volatile gentleman of that appellation, who would call on his neighbors, and be gone before his name could be announced.
Another explanation is that it is from a line in an “old play,” which James Halliwell in his 1846 Dictionary of Archaic and Provincial Words gives as:
A warke it ys as easie to be done.
As tys to saye Jacke! robys on.
But we don’t know what play, when it was written, or by whom.
There are also several explanations that we can discount because they are chronologically impossible. One of the more interesting of these involves the playwright Richard Brinsley Sheridan. Supposedly, while serving as a Member of Parliament and making a speech against government bribery, he responded to calls to name the guilty parties by looking at John Robinson, secretary of the treasury, and saying, “yes, I could name him as soon as I could say ‘Jack Robinson.’” If the story is true (which is open to question), Sheridan was punning on an existing phrase, because he did not join Parliament until 1780, after the phrase was already established.
There was popular song in the early 19th century titled Jack Robinson. By Thomas Hudson, this song about a sailor with that name also appears far too late for it to be the inspiration for the phrase.
Similarly in the 19th century, Jack Robinson became a slang term for penis. It is possible that the phrase gave rise to this slang sense, but the reverse is not possible.
Copyright 1997-2016, by David Wilton