Also found in: Dictionary, Thesaurus, Encyclopedia, Wikipedia.
Unintentionally happening at the same time or in the same way as something else. By coincidence, my sister and I bought our mom the same sweater for her birthday. I didn't just come to the same place as you by coincidence—your assistant told me where I could find you.
the long arm of coincidence
The broad, far-reaching power or influence of coincidence. The film relies too heavily on the long arm of coincidence to bring its many characters and convoluted plot points together. We actually grew up in the same town in Kansas, but through the long arm of coincidence, met and fell in love in India nearly 30 years later!
by an accidental and strange similarity; by an unplanned pairing of events or occurrences. We just happened to be in the same place at the same time by coincidence. By coincidence, the circus was in town when I was there. I'm glad because I love circuses.
Through an accidental simultaneous occurrence, as in By coincidence both researchers discovered the same solution. [Mid-1600s] Also see by chance.