Popular English Idioms:

This list of popular English Idioms is "jam packed" with definitions and examples for idioms whose main word begins with the letter "J." When you're ready, just "jump in" and get started. Also, if you want to see idioms for other letters of the alphabet, click here to go to the main idioms page

A quick reminder : an idiom is a group of words whose meaning is different from the individual words if you looked them up separately in the dictionary.

Popular English Idioms Beginning with "J"


jack of all trades:  someone who can do many different types of things.

  • My mom’s a jack of all trades — she learned how to do the repairs around the house; does all the housework and cooking; and can even fix our computers.
  • Sarah is the jack of all trades  in the office whereas I just work on accounting tasks.
  • In track and field, decathletes are truly jacks of all trades. 

jack up something (jack something up):  to instantly increase something very much.

  • Credit card companies wait until their customers have high balances on their accounts and then they jack up their interest rates.
  • After the war started, gas stations jacked their prices up.
  • My neighbors just jacked the music up  and this time I'm going to call the police.


hit the jackpot:  to achieve great success (like winning the jackpot — a large amount of money in gambling games).

  • Lady Gaga hit the jackpot  with her first two CDs.
  • We’re going to hit the jackpot  with the new software we’ve developed.


jam on the brakes:  to quickly and strongly use the brakes to stop a vehicle or car.

  • I had to jam on the brakes  to avoid hitting a dog this morning and I was shaking for the rest of the ride to work.
  • Don't jam on the brakes  when you hit an icy patch on the road. Instead, take your foot off the brake and turn your wheels into the direction the rear of you car is sliding.

jam packed:  very crowded or full.

  • The concert was jam packed  with so many people it was hard to see anything.
  • This green juice is jam packed  with lots of vitamins and nutrients.

jam on it:  hurry or move.

  • We'd better jam on it  or we'll be late to our appointment.
  • If the security people don't  jam on it  we're going to miss our flight.


one’s jaw drops (open):  to show great surprise.

  • When our son saw that we bought him a new car for his birthday, his jaw dropped.
  • When they announced I was the one who got the promotion, everyone’s jaw dropped, including mine.
  • My dad’s jaw is going to drop open  when he sees my report card.


jazz up something (jazz something up):  to make something more interesting, exciting... read more

  • I love this café because they always jazz up their drinks  with whipped cream and flavored syrups.
  • We’re going to jazz this conference room up  with streamers and balloons for the holiday party.

and all that jazz:  and all those other similar things.

  • On the first day of class they’ll give you the syllabus, booklist, tell you about tests and grading, and all that jazz.
  • I really love the holidays with the festive decorations, cheerful music and all that jazz.

be jazzed about something:  to be excited about something.

  • I’m so jazzed about my new bike  I’m going to ride it to work every day.
  • Are you jazzed about spring break  this year?
  • We're really jazzed about going camping  in the mountains next week.


in jeopardy:  in danger.

  • You’re putting your scholarship in jeopardy  by partying and not studying.
  • The flowers we recently planted are in jeopardy  because of the unexpected cold weather we've been having.


jerk someone around:  to lie and try to deceive someone about something.

  • I thought my boyfriend was serious about our relationship but he was just jerking me around  and he never planned to marry me.
  • The sales man was jerking us around  when he said he’d give us a discount.


in jest:  joking.

  • When I said I quit my job it was only in jest.
  • Don't get upset, he always says things in jest.


do the job:  to get the same result as another method.

  • If you don’t have lemon juice, lime juice will do the job.
  • Normally, I stay at luxury hotels but as long as the hotel is clean it'll do the job.
  • The button on my colleague's pants came off and no one had a sewing kit, so she used a binder clip to temporarily do the job.

on the job:  while working.

  • We have a strict rule that there’s no checking Facebook on the job.
  • I can’t believe you’re watching videos on your phone while on the job!  What if someone sees you?


jockey for position:  to try to move around to get the best position or advantage.

  • After my boss said she was leaving the company, everyone started jockeying for position  to run the department.
  • Before the bride threw the bouquet, I jockeyed for position  and caught it.


jog one’s memory:  to try to cause someone to remember something.

  • Does this empty pack of cigarettes jog your memory  about your promise to quit smoking?
  • I’m trying to jog my memory  about where I put my keys.


join forces (with someone):  to unite with someone or work together.

  • We should join forces  and go running every day after school to lose weight.
  • Our tennis and lacrosse teams joined forces  to fund raise for new uniforms.

join hands (with someone):  to clasp hands, hold hands with others.

  • I love it at church when we join hands  and wish each other peace.
  • When the minister asked the bride and groom to join hands  I already started to cry.
  • At the end of the meeting, we all joined hands with each other  and it was a very moving experience.

join in:  to participate in an activity.

  • Could I join in  on your support group this evening?
  • Why don’t you join in  the discussion we're having?

join the fray:  participate in a fight or argument that had already started.

  • My son always looks for any opportunity to join the fray  whenever a fight breaks out at school.
  • I couldn't believe my coworker joined the fray  in criticizing our boss' proposal.

joined at the hip:  together with someone all the time, closely connected.

  • My son and our little puppy have been joined at the hip  ever since we brought him home from the shelter.
  • Unfortunately, my boss and I are always joined at the hip  during out-of-town conferences so I won’t be able to see you.


no joke:  it’s a serious matter.

  • I’m sorry but this is no joke — I suggest you stop laughing and listen to me carefully or I’ll call your parents.
  • If you're planning on studying economics you need to understand it's no joke  and you'll have to study a lot to do well.

play a joke on someone:  to do something to make someone feel embarrassed or dumb.

  • My friends played a joke on me  pretending that they forgot my birthday and I was almost in tears.
  • My boyfriend always plays jokes on his friends  but he gets really upset when they do the same to him.

take a joke:  to keep good humor when someone makes fun of you.

  • There are five boys in my family and I’m the only girl. Luckily, I can take a joke  because they’re always tormenting me.
  • Don't ever tease the receptionist because she cannot take a joke.


jot something down (jot down something):  write something quickly.

  • Grab a pencil and jot down  this number for me.
  • Sure, you can see my notes but I only jotted down  a few ideas since I prefer to just listen carefully during lectures.


jump for joy:  to be very excited and happy about something.

  • When the number of my YouTube subscribers grew to 1,000 people I was jumping for joy.
  • We jumped for joy  when we learned our parents were getting a puppy.


you can’t judge a book by its cover:  it's not good to decide about something based on its outward appearance only.

  • In Los Angeles, you can’t judge a book by its cover  because some of the richest people shop in jeans and a T-shirt.
  • When Susan Boyle sang on Britain's Got Talent  she proved perfectly that you can't judge a book by its cover.

judge someone / something on its own merits:  evaluate something by its own achievements and accomplishments.

  • I really hope this company will judge each applicant by his or her own merits  but I think it’s more about who you know.
  • Fortunately, everyone is judged on his or her own merits  when it's time to give out promotions.


against one’s better judgment:  making a decision that isn’t the best one for you.

  • A year ago, I decided to lend my friend $2,000 against my better judgment  and now she hasn’t paid me back a penny and avoids me.
  • Taking this job is against my better judgement  because it's so far from my home but I really need the money and the salary is good.

pass judgment on someone / something:  to make a strong opinion about something.

  • Dad, before you pass judgment on my boyfriend,  I want to tell you he’s a straight-A student and his father’s a doctor.
  • I never pass judgment on other people  until I've learned more about them.
  • When we go to China I recommend that you don't pass judgment on the food  until you've had a chance to try it.

sit in judgment of someone / something:  to decide if someone is guilty / innocent, or good / bad.

  • You have no right to sit in judgment of who I date — you’re supposed to be my friend and support me.
  • It's easy for you to sit there in judgment of poor people  when you've been able to easily get good jobs with good salaries from your parents' connections.


get a jump on someone / something:  to act before someone / something to get an early advantage.

  • We left an hour early for the beach to get a jump on weekend traffic.
  • We're going to get a jump on the competition  by giving free samples to all of the residents as they move into the new housing complex.

jump all over someone:  to severely criticize, blame or accuse someone.

  • When I was 15 minutes late coming home my dad jumped all over me  and searched my purse.
  • Don’t jump all over me  just because I disagree with you.

jump at something:  to quickly and eagerly take an opportunity.

  • jumped at the first opportunity  to work so that’s how I started mowing lawns when I was 10 years old.
  • I would jump at the chance  to work in Apple's corporate office—even if I started as a receptionist or administrative assistant.

jump down someone’s throat:  to severely criticize someone.

  • Don’t jump down his throat  just because you disagree or he’ll stop talking to us.
  • I felt so badly for my boss this morning because the director jumped down his throat  for something that wasn't even her fault.

jump in:  to quickly get involved in something.

  • Don’t try to jump in  when your mother and I are talking.
  • Fee free to jump in  and help us with the yard work.
  • Without thinking, that man just jumped in  and helped rescue two children from the fire.

jump in with both feet:  to quickly and completely get involved with something.

  • Whenever I start a new sport, I jump in with both feet  and buy all the equipment, clothing and lessons.
  • Unless you're going to jump in with both feet,  don't quit your job to become a writer.

jump off the deep end:  to take immediate and drastic action.

  • Don’t jump off the deep end  and move from this apartment just because you saw one little mouse.
  • After my husband hit me in front of the kids, I knew I had to jump off the deep end  and move far away from him.

jump off the shelves:  to sell very quickly.

  • Sorry, we don’t have any more of those phones left — when they went on sale last Friday they jumped off the shelves.
  • These hand-painted bird houses are really jumping off the shelves.

(almost / nearly) jump out of one’s skin:  to be suddenly very frightened.

  • When I was walking to my car, a rat ran out in front of me and I almost jumped out of my skin.
  • Don’t sneak up on me like that — I almost jumped out of my skin.

jump the gun:  to start before it’s time to begin.

  • Last year we jumped the gun  with our sales promotion so we better find a better date and make sure everyone is ready this year.
  • Be careful not to jump the gun  with Jessica. I suggest at least a year-long engagement before you get married.

go / jump through hoops:  to do a series of difficult or unpleasant things in order to get something you want or something you need to do... read more

  • My husband jumped through hoops  to get my son into private school and he got expelled the second day!
  • Working in the private sector is amazing—I used to have to go through hoops  just to get a new pen and notebook.

jump to conclusions:  to assume something or make a decision without carefully thinking about it.

  • We found these condoms in your purse — but before we jump to conclusions  we wanted to talk to you.
  • I'm tired of you always jumping to conclusions.  How many times have you been wrong when you didn't wait to get all of the information?


the jury is still out:  a decision still hasn’t been made.

  • “Are you going to Europe the summer?” “The jury still out  but I’ll find out if my holiday request is approved very soon.”
  • The jury is still out  about the new receptionist—she's doing okay at the job but she's also been late several times this week.


just in case:  if something happens.

  • Just in case  I’m late this evening, please take the dog out for a walk.
  • You better take some cash with you just in case  they don’t accept credit cards.

just now:  a short time ago.

  • Just now  on the news they announced there was a terrible earthquake in Japan.
  • "I'm so sorry to keep you waiting?" "Don't worry, I arrived just now."

just what the doctor ordered:  the exact thing that is needed.

  • Thanks so much for the scented candles — it’s just what the doctor ordered.
  • These towels and blankets are just what the doctor ordered  because last night a dozen dogs arrived at the shelter.

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You can also find many idiom definitions by using one of the online learner's dictionaries.

Practice popular English idioms beginning with "J"

Now that you've learned many of the popular English idioms that start with "J," it's time to practice by creating a few of your own sentences. This will help you remember the expressions.

There's no substitute for practice. I wish I could do it for you but it's up to you to make the effort to learn. I promise that the more you practice, the more you will remember. And, don't worry, I will revise any mistakes in your practice sentences.

Write your practice sentences in the comments section below.

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