coincidence

noun

• 1a remarkable concurrence of events or circumstances without apparent causal connection:it was a coincidence that she was wearing a jersey like Laura’s [mass noun]:they met by coincidence

• 2 [mass noun] the fact of corresponding in nature or in time of occurrence:the coincidence of interest between the mining companies and certain politicians

• 3 Physics the presence of ionizing particles or other objects in two or more detectors simultaneously, or of two or more signals simultaneously in a circuit.