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.
jack of all trades: someone who can do many different types of things. Example: 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... read more
jack up something (jack something up): to instantly increase something very much. Example: Credit card companies wait until their customers have high balances on their accounts and then they jack up their interest rates... read more
hit the jackpot: to achieve great success (like winning the jackpot—a large amount of money in gambling games). Example: Lady Gaga hit the jackpot with her first two CDs... read more
jam on the brakes: to quickly and strongly use the brakes to stop a vehicle or car. Example: 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... read more
jam packed: very crowded or full. Example: The concert was jam packed with so many people it was hard to see anything... read more
jam on it: hurry or move. Example: We'd better jam on it or we'll be late to our appointment... read more
one’s jaw drops (open): to show great surprise. Example: When our son saw that we bought him a new car for his birthday, his jaw dropped... read more
jazz up something (jazz something up): to make something more interesting, exciting. Example: The barista jazzed up my hot cocoa with a cute spider web... read more
and all that jazz: and all those other similar things. Example: On the first day of class they’ll give you the syllabus, book list, tell you about tests and grading, and all that jazz... read more
be jazzed about something: to be excited about something. Example: I’m so jazzed about my new bike I’m going to ride it to work every day... read more
in jeopardy: in danger. Example: You’re putting your scholarship in jeopardy by partying and not studying... read more
jerk someone around: to lie and try to deceive someone about something. Example: I thought my boyfriend was serious about our relationship but he was just jerking me around and he never planned to marry me... read more
in jest: joking. Example: When I said I quit my job it was only in jest... read more
do the job: to get the same result as another method. Example: If you don’t have lemon juice, lime juice will do the job... read more
on the job: while working. Example: We have a strict rule that there’s no checking Facebook on the job... read more
jockey for position: to try to move around to get the best position or advantage. Example: After my boss said she was leaving the company, everyone started jockeying for position to run the department... read more
jog one’s memory: to try to cause someone to remember something. Example: Does this empty pack of cigarettes jog your memory about your promise to quit smoking?.. read more
join forces (with someone): to unite with someone or work together. Example: We should join forces and go running every day after school to lose weight... read more
join hands (with someone): to clasp hands, hold hands with others. Example: I love it at church when we join hands and wish each other peace... read more
join in: to participate in an activity. Example: Could I join in on your support group this evening?.. read more
join the fray: participate in a fight or argument that had already started. Example: My son always looks for any opportunity to join the fray whenever a fight breaks out at school... read more
joined at the hip: together with someone all the time, closely connected. Example: My son and our little puppy have been joined at the hip ever since we brought him home from the shelter... read more
no joke: it’s a serious matter. Example: I’m sorry but this is no joke—I suggest you stop laughing and listen to me carefully or I’ll call your parents... read more
play a joke on someone: to do something to make someone feel embarrassed or dumb. Example: My friends played a joke on me pretending that they forgot my birthday and I was almost in tears... read more
take a joke: to keep good humor when someone makes fun of you. Example: 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... read more
jot something down (jot down something): write something quickly. Example: Grab a pencil and jot down this number for me... read more
jump for joy: to be very excited and happy about something. Example: When the number of my YouTube subscribers grew to 1,000 people I was jumping for joy... read more
you can’t judge a book by its cover: it's not good to decide about something based on its outward appearance only. Example: 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... read more
judge someone / something on its own merits: evaluate something by its own achievements and accomplishments. Example: 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... read more
against one’s better judgment: making a decision that isn’t the best one for you. Example: 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... read more
pass judgment on someone / something: to make a strong opinion about something. Example: 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... read more
sit in judgment of someone / something: to decide if someone is guilty/innocent, or good/bad. Example: You have no right to sit in judgment of who I date—you’re supposed to be my friend and support me... read more
get a jump on someone/something: to act before someone/something to get an early advantage. Example: We left an hour early for the beach to get a jump on weekend traffic... read more
jump all over someone: to severely criticize, blame or accuse someone. Example: When I was 15 minutes late coming home my dad jumped all over me and searched my purse... read more
jump at something: to quickly and eagerly take an opportunity. Example: I jumped at the first opportunity to work so that’s how I started mowing lawns when I was 10 years old... read more
jump down someone’s throat: to severely criticize someone. Example: Don’t jump down his throat just because you disagree or he’ll stop talking to us... read more
jump in: to quickly get involved in something. Example: Don’t try to jump in when your mother and I are talking... read more
jump in with both feet: to quickly and completely get involved with something. Example: Whenever I start a new sport, I jump in with both feet and buy all the equipment, clothing and lessons... read more
jump off the deep end: to take immediate and drastic action. Example: Don’t jump off the deep end and move from this apartment just because you saw one little mouse... read more
jump off the shelves: to sell very quickly. Example: Sorry, we don’t have any more of those phones left—when they went on sale last Friday they jumped off the shelves... read more
(almost / nearly) jump out of one’s skin: to be suddenly very frightened. Example: When I was walking to my car, a rat ran out in front of me and I almost jumped out of my skin... read more
jump the gun: to start before it’s time to begin. Example: Last year we jumped the gun with our sales promotion, so this year we better find a better date and make sure everyone is ready... read more
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. Example: My husband jumped through hoops to get my son into private school and he got expelled the second day!.. read more
jump to conclusions: to assume something or make a decision without carefully thinking about it. Example: We found these condoms in your purse—but before we jump to conclusions we wanted to talk to you... read more
the jury is still out: a decision still hasn’t been made. Example: “Are you going to Europe the summer?” “The jury still out but I’ll find out if my holiday request is approved very soon.”.. read more
just in case: if something happens. Example: Just in case I’m late this evening, please take the dog out for a walk... read more
just now: a short time ago. Example: Just now on the news they announced there was a terrible earthquake in Japan... read more
just what the doctor ordered: the exact thing that is needed. Example: Thanks so much for the scented candles—it’s just what the doctor ordered... read more
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You can also find many idiom definitions by using one of the online learner's dictionaries.
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.