coincidence
UK: /kəʊˈɪnsɪdəns/ | US: /koʊˈɪnsɪdəns/
n. an occasion when two or more similar things happen at the same time by chance
n. a remarkable concurrence of events or circumstances without apparent causal connection
The word "coincidence" traces back to Latin coincidere, combining co- (together) + in- (upon) + cidere (to fall). The literal sense was "to fall upon together," implying events converging by chance. Over time, it evolved in French (coïncidence) and English to emphasize unexpected alignments without planned causality. The morpheme cid (from Latin cadere, "to fall") appears in related words like "accident" (an unforeseen event) and "deciduous" (falling off).
Running into you here is such a coincidence!
By sheer coincidence, we both wore the same dress to the party.
The timing of their arrival was no coincidence—they had planned it secretly.
Scientists often distinguish between correlation and coincidence.
It’s a strange coincidence that they share the same birthday.