J

Jack Frost
If everything has frozen in winter, then Jack Frost has visited.
Jack-of-all-trades
A jack-of-all-trades is someone that can do many different jobs.
Jane Doe
Jane Doe is a name given to an unidentified female who may be party to legal proceedings, or to an unidentified person in hospital, or dead.
Jersey justice
Jersey justice is very severe justice.
Jet-black
To emphasise just how black something is, such as someone’s hair, we can call it jet-black.
Jobs for the boys
Where people give jobs, contracts, etc, to their friends and associates, these are jobs for the boys.
Jockey for position
If a number of people want the same opportunity and are struggling to emerge as the most likely candidate, they are jockeying for position.
John Doe
John Doe is a name given to an unidentified male who may be party to legal proceedings, or to an unidentified person in hospital, or dead.
John Q Public
John Q Public is the typical, average person.
Johnny-come-lately
A Johnny-come-lately is someone who has recently joined something or arrived somewhere, especially when they want to make changes that are not welcome.
Juggle frogs
If you are juggling frogs, you are trying to do something very difficult.
Jump on the bandwagon
If people jump on the bandwagon, they get involved in something that has recently become very popular.
Jump the gun
If you jump the gun, you start doing something before the appropriate time.
Jump through hoops
If you are prepared to jump through hoops for someone, you are prepared to make great efforts and sacrifices for them.
Jungle out there
If someone says that it is a jungle out there, they mean that the situation is dangerous and there are no rules.
Jury’s out
If the jury’s out on an issue, then there is no general agreement or consensus on it.
Just coming up to
If the time is just coming up to ten o’clock, it means that it will be ten o’clock in a very few seconds.
Just deserts
If a bad or evil person gets their just deserts, they get the punishment or suffer the misfortune that it is felt they deserve.
Just in the nick of time
If you do something in the nick of time, you just manage to do it just in time, with seconds to spare.
Just off the boat
If someone is just off the boat, they are naive and inexperienced.