english
1
general::
Through an accidental simultaneous occurrence, as in By coincidence both researchers discovered the same solution. [Mid-1600s] Also see BY CHANCE.
American Heritage Idioms
2
general::
Phrase(s): by coincidence 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.
McGrawhill's American Idioms And Phrasal Verbs