launder (v.) Look up launder at Dictionary.com
1660s, "to wash linen," from noun launder "one who washes" (especially linen), mid-15c., a contraction of lavender, from Old French lavandier "washer, launderer" (12c.), from Medieval Latin lavandaria "a washer," which is ultimately from Latin lavare "to wash" (see lave). Criminal banking sense first recorded 1961, from notion of making dirty money clean; the word in this sense was brought to widespread use during U.S. Watergate scandal, 1973. Related: Laundered; laundering.