n a loud resonant repeating noise
n a serious accident (usually involving one or more vehicles)
n a sudden large decline of business or the prices of stocks (especially one that causes additional failures)
n the act of colliding with something
n (computer science) an event that causes a computer system to become inoperative
v fall or come down violently
v move with, or as if with, a crashing noise
v undergo damage or destruction on impact
v move violently as through a barrier
v break violently or noisily; smash;
v occupy, usually uninvited
v make a sudden loud sound
v enter uninvited; informal
v cause to crash
v hurl or thrust violently
v undergo a sudden and severe downturn
v stop operating
v sleep in a convenient place