| Jacobean: | the Irish discoverer of coffee. |
| Japanese Spitz: | oriental kebabs |
| Jigsaw Puzzle: | Riverdance: The Show. |
| Jonathon (n): | a fund-raising activity in which people pledge money to watch celebrities spend long periods on the loo. Also spelled "john-a-thon". |
| Jubilee Lion: | one of the more feral of HM's corgies. |
| Jurisdiction (n): | the crime of talking in court when you should really be listening to the defence lawyer. |