AMERICAN IDIOMS STARTING WITH J
Jam-packed:
Very crowded. ex. "The stadium was jam packed on Saturday."
(To) jam on the brakes:
To hit/ step on the brakes suddenly to stop the car.
Jack-of-all-trades:
A person who knows how to do a lot of different things.
(To) jump all over someone/ jump down someone's throat:
To criticize or blame someone. ex. "As soon as I brought up going out with my friends, she jumped all over me."
(To) jump the gun:
To get something started too soon. To start too soon. ex. "We have to do a lot more work before we launch this product. We don't want to jump the gun."
(To) jump at:
To quickly accept. ex. "The journalist jumped at the chance to interview Madonna."
Just about:
Almost. ex. "I'm just about finished."
Just now:
Just a minute ago.
Just what the doctor ordered:
Exactly what is needed. ex. "This vacation is great! It's just what the doctor ordered."