Launder (verb)

1. To wash (clothes or linens).
2. To clean (money or other assets) obtained illegally in order to make it appear legal.
3. To process (a liquid or gas) in order to remove impurities or pollutants.

Origin:

Late middle english (in the sense "wash clothes"): from old french lavandre, from latin lavandus "to be washed", gerundive of lavare.

Examples:

1. She laundered the clothes and hung them out to dry.
2. The laundromat was busy with people laundering their clothes.
3. The criminal laundered the money through a series of offshore accounts.
4. The company laundered the emissions to make them appear legal.
5. The water was laundered to remove pollutants before it was released into the river.