A remarkable occurrence of events having a mutual impact, occurring without any apparent causal connection.

संयोग

English Usage: It was just a coincidence that they met on the same day.

Hindi Usage: यह केवल संयोग था कि वे एक ही दिन मिले।

The action of correcting something.

सुधार

English Usage: The teacher made a correction on my paper.

Hindi Usage: शिक्षक ने मेरी पत्रिका पर सुधार किया।