Quiz: Remember the definition of mal de mer?
1520s, "footman, running footman, valet," from Middle French laquais "foot soldier, footman, servant" (15c.), of unknown origin; perhaps from Old Provençal lacai, from lecai "glutton, covetous," from lecar "to lick." Alternative etymology is via French from Catalan alacay, from Arabic al-qadi "the judge." Yet another guess traces it through Spanish lacayo, from Italian lacchè, from Modern Greek oulakes, from Turkish ulak "runner, courier." This suits the original sense better, but OED says Italian lacchè is from French. Sense of "servile follower" appeared 1580s. As a political term of abuse it dates from 1939 in communist jargon.