1719, "natural or artificial embankment to prevent overflow of a river," from New Orleans French levée "a raising, a lifting; an embankment," from French levée, literally "a rising" (as of the sun), noun use of fem. past participle of lever "to raise," from Latin levare "to raise, lift up; make lighter" (from PIE root *legwh- "not heavy, having little weight"). They also were used as landing places.
"morning assembly held by a prince or king" (originally upon rising from bed), 1670s, a spelling intended to represent the pronunciation of French lever "a raising," noun use of verb meaning "to raise" (see levee (n.1)), or else from a variant form of levée in French, which, however, "has not the meaning 'a reception'" [Century Dictionary]. By mid-18c. the word in English was used of assemblies or receptions held at any hour.