Yes, lune is in the scrabble dictionary.

What dies Lune mean?

noun. anything shaped like a crescent or a half moon. a crescent-shaped figure bounded by two arcs of circles, either on a plane or a spherical surface.

Is this word OK for scrabble?

"OK" is now OK to play in a game of Scrabble. The two-letter word is one of 300 new additions to the latest version of the Official Scrabble Players Dictionary, which Merriam-Webster released on Monday. ... Not all Scrabble players are OK with OK, however, especially at the game's highest levels.