An occurrence of events that happen at the same time by chance.

A surprising or remarkable occurrence.

आश्चर्यजनक घटना

English Usage: Their meeting was a coincidence that changed their lives forever.

Hindi Usage: उनकी मुलाकात एक संयोग थी जिसने उनकी ज़िंदगी हमेशा के लिए बदल दी।