1 a [no obj] : to hit something hard enough to cause serious damage or destruction
▪ Investigators are still trying to determine why the airplane crashed. [=why the airplane hit the ground] — often + into ▪ The car crashed into the fence/wall/guardrail. ▪ She crashed into another car. ▪ A large meteorite may have crashed into the Earth 65 million years ago.
b [+ obj] : to damage (a vehicle) by causing it to hit something
▪ She crashed the car into a tree, but no one was hurt. ▪ He has crashed two cars, a truck, and a motorcycle. 2 a always followed by an adverb or preposition [no obj] : to make a loud noise by falling, hitting something, etc.
▪ We listened to the waves crashing against the shore. ▪ The stuntman crashed through the window on a motorcycle. ▪ The walls crashed down around them. ▪ He came crashing [=tearing] through the woods. ▪ The books crashed to the floor. ▪ The whole stack of cans came crashing down. [=fell down with a lot of noise and force] — sometimes used figuratively ▪ The whole theory came crashing down when it was revealed that some of the supporting evidence had been falsified. ▪ His world came crashing down when he lost his job.
b [no obj] : to make a loud noise
▪ The cymbals crashed and the trumpets blew. ▪ Thunder crashed as the rain started to pour.
c [+ obj] : to cause two things to hit against each other and make a loud noise
▪ He crashed the cymbals together. 4 a [no obj] of a computer : to stop working suddenly
▪ My computer keeps crashing.
b [+ obj] : to cause (a computer) to stop working suddenly
▪ This program always crashes my computer. 5 [no obj] informal a : to go to sleep
▪ I was exhausted after the long flight, so I just checked into the hotel and crashed.
b : to stay or live for a short time with someone
▪ You can crash [=sleep] here tonight. ▪ She's crashing with friends for a few days while her apartment is being repaired. 6 [no obj] of a business, price, market, etc. : to go down in value very suddenly and quickly
▪ They lost thousands of dollars when the stock market crashed. 7 [+ obj] informal : to go to (a party) without being invited
▪ He tried to crash the party but they wouldn't let him in. 8 [+ obj] US, sports : to move very quickly and forcefully toward (something, such as the goal in ice hockey)
▪ The players crashed the net.