before (one) can say Jack Robinson(redirected from before they can say Jack Robinson)
before (one) can say Jack Robinson
Quickly or suddenly. (The true identity of Jack Robinson is unknown.) I'm not far from your house, so I'll be there before you can say Jack Robinson.
before you can say Jack Robinsonand quicker than you can say Jack Robinson
Fig. almost immediately. (Often found in children's stories.) And before you could say Jack Robinson, the bird flew away. I'll catch a plane and be there quicker than you can say Jack Robinson.
before you can say Jack Robinson
Also, quicker than you can say Jack Robinson. Almost immediately, very soon, as in I'll finish this book before you can say Jack Robinson. This expression originated in the 1700s, but the identity of Jack Robinson has been lost. Grose's Classical Dictionary (1785) said he was a man who paid such brief visits to acquaintances that there was scarcely time to announce his arrival before he had departed, but it gives no further documentation. A newer version is before you know it, meaning so soon that you don't have time to become aware of it (as in He'll be gone before you know it).
before you can say Jack Robinsonvery quickly or suddenly. informal
This expression was in use in the late 18th century, but neither an early 19th-century popular song about Jack Robinson nor some mid 19th-century attempts to identify the eponymous Jack Robinson shed any light on its origins.