Judder is a verb that means to shake something with force.

The origin of our word of the day is unclear, but its birth seems to have been imitative, meaning the word may have been word with somebody imitating the sound of something being juddered. Here’s an example:

Ellie, an old 1991 El Dorado, was a magnificent car. After a while, you had to judder the keys in the ignition to get her to start, but once you gave it a good shake, she was one smooth ride.