Definitions of crash:

• noun:   the act of colliding with something

  Example: "His crash through the window"

• noun:   a serious accident (usually involving one or more vehicles)

  Example: "They are still investigating the crash of the TWA plane"

• noun:   a sudden large decline of business or the prices of stocks (especially one that causes additional failures)
• noun:   (computer science) an event that causes a computer system to become inoperative

  Example: "The crash occurred during a thunderstorm and the system has been down ever since"

• noun:   a loud resonant repeating noise
• verb:   move with, or as if with, a crashing noise

  Example: "The car crashed through the glass door"

• verb:   occupy, usually uninvited

  Example: "My son's friends crashed our house last weekend"

• verb:   stop operating

  Example: "My computer crashed last night"

• verb:   undergo a sudden and severe downturn

  Example: "The economy crashed"

• verb:   hurl or thrust violently
• verb:   undergo damage or destruction on impact

  Example: "The plane crashed into the ocean"

• verb:   break violently or noisily; smash;
• verb:   cause to crash

  Example: "The terrorists crashed the car into the gate of the palace"

• verb:   fall or come down violently

  Example: "The branch crashed down on my car"

• verb:   move violently as through a barrier

  Example: "The terrorists crashed the gate"

• verb:   enter uninvited; informal

  Example: "Let's crash the party!"

• verb:   sleep in a convenient place

  Example: "You can crash here, though it's not very comfortable"