c.1530, from O.Fr.
lavanderie, from L.
lavendaria, pl. of
lavandarium "things to be washed," from
lavare "to wash" (see
lave). The verb
launder "to wash linen" is from 1664; criminal banking sense first recorded 1961, from notion of making dirty money seem clean; brought to widespread use during Watergate scandal, 1973.
Laundry list in figurative sense is from 1958.
Laundromat is from 1943, originally a proprietary name by Westinghouse.