Meaning of “crash” - Learner’s Dictionary

crash

noun [ C ] uk us /kræʃ/
VEHICLE

B1 an accident in which a vehicle hits something:

a car/plane crash
NOISE

B2 a sudden, loud noise made when something falls or breaks:

I heard a crash and hurried into the kitchen.
BUSINESS

an occasion when the value of a country's businesses suddenly falls by a large amount:

He lost a lot of money in the stock market crash of 1929.

(Definition of “crash noun” from the Cambridge Learner’s Dictionary © Cambridge University Press)