accident accident /ˈæksɪdənt/

noun

1. () An unfortunate mishap; especially one causing damage or injury  ( accident )
   an unfortunate mishap; especially one causing damage or injury
    My sister had an accident while riding her bike
   My sister had an accident while riding her bike
   
   
2. () Anything that happens suddenly or by chance without an apparent cause  ( chance event , fortuity , stroke , accident )
   anything that happens suddenly or by chance without an apparent cause
    Winning the lottery was a happy accident
   winning the lottery was a happy accident
    The pregnancy was a stroke of bad luck
   the pregnancy was a stroke of bad luck
    It was due to an accident or fortuity
   it was due to an accident or fortuity