Quiz: Remember the definition of mal de mer?
c.1500, "moonlight," from moon (n.) + shine (n.). In figurative use, implying "appearance without substance," from late 15c.; perhaps connected in that sense with notion of "moonshine in water" (cf. moonraker). Meaning "illicit liquor" is attested from 1785 (earliest reference is to that smuggled on the coasts of Kent and Sussex); moonlight also occasionally was used in this sense early 19c. As a verb from 1883. Related: Moonshiner (1860).