The process of making large sums of money but hiding the source of the earnings or generating revenue through illegal activities such as drug trafficking, corruption or gambling or fraud is called money laundering.

Example:
Popular examples are the Coalgate scam, the Vijay Mallya case, the 2G scam and the Nirav Modi PNB bank fraud.
It is a serious financial crime where an individual or organisation tries to make the ‘dirty’ money appear legitimate.