1 [uncountable and countable] when two things happen at the same time, in the same place, or to the same people in a way that seems surprising or unusual [↪ coincide, coincidental]:
'I'm going to Appleby tomorrow.' ' What a coincidence!I'm going up there too.'
by coincidence
By coincidence, John and I both ended up at Yale.
sheer/pure coincidence (=completely by chance)
I didn't set out to find you - it's sheer coincidence that I should walk along the same street.
not a coincidence/more than coincidence
After the fourth attack on her car she was convinced that the vandalism was more than just coincidence.
It was a happy coincidence that Robert arrived at the same time.
2 [singular] formal when two ideas, opinions etc are the same
coincidence of
a coincidence of interest between the mining companies and certain politicians

Dictionary results for "coincidence"
Dictionary pictures of the day
Do you know what each of these is called?
What is the word for picture 1? What is the word for picture 2? What is the word for picture 3? What is the word for picture 4?
Click on any of the pictures above to find out what it is called.