laun ‧ der /ˈlɔːndə $ ˈlɒːndər/ BrE AmE verb [transitive]
[ Date: 1500-1600 ; Origin: launder 'someone who washes clothes' (14-17 centuries) , from French lavandier , from Latin lavare ; ⇨ ↑ lavatory ]
1 . to put money which has been obtained illegally into legal businesses and bank accounts, so that you can hide it or use it:
He was jailed for laundering drug money.
2 . formal to wash and ↑ iron clothes, sheets etc