Launder
Middle English (as a noun denoting a person who washes linen): contraction of lavender, from Old French lavandier, based on Latin lavanda ‘things to be washed’, from lavare ‘to wash’.
wiktionary
Contracted from Middle English lavender, from Old French lavandiere, from Late Latin lavandena, from Latin lavō(“I wash”).
etymonline
launder (v.)
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" (from PIE root *leue- "to wash"). 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.
