Noun accident has 2 senses
  1. accident - a mishap; especially one causing injury or death
    --1 is a kind of
    mishap, misadventure, mischance
    --1 has particulars:
     collision; crash, wreck; injury, accidental injury; shipwreck, wreck; fatal accident, casualty
  2. accident, fortuity, chance event - anything that happens by chance without an apparent cause
    --2 is a kind of happening, occurrence, natural event
    --2 has particulars:
     hap; break, good luck, happy chance; coincidence, happenstance; lottery