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"La luna" is a form of "luna", a noun which is often translated as "moon". "El sol" is a form of "sol", a noun which is often translated as "sun". Learn more about the difference between "la luna" and "el sol" below.
la luna(
loo
-
nah
)A feminine noun is almost always used with feminine articles and adjectives (e.g., la mujer bonita, la luna llena).
1. (astronomy)
a. window 
Los ladrones empotraron el coche en la luna de la joyería.The thieves smashed the car into the jewelry store window.
a. mirror 
La imagen que la luna le devolvía era la de una mujer atractiva, de mediana edad.The image reflected in the mirror was that of an attractive, middle-aged woman.
4. (automobile)
a. windshield  (United States)
Regionalism used in the United States
La luna delantera del coche se rompió a causa del impacto de una piedra.The front windshield broke because it was hit by a stone.
b. windscreen  (United Kingdom)
Regionalism used in the United Kingdom
La luna tintada de mi coche nuevo ayuda mucho con visibilidad.The tinted windscreen on my new car really helps with visibility.
el sol(
sohl
)A masculine noun is used with masculine articles and adjectives (e.g., el hombre guapo, el sol amarillo).
1. (astronomy)
a. sun 
Galileo Galilei declaró que la tierra gira alrededor del sol.Galileo Galilei declared that the Earth revolves around the sun.
2. (light rays)
3. (familiar)
4. (music)
a. G 
Para tocar sol en la trompeta, hay que dejar las válvulas abiertas.In order to play G on the trumpet, you need to leave the valves open.
c. so  (solfege) (United States)
Regionalism used in the United States
Ahora puedo tocar casi todas las notas salvo el sol.Now I can play almost every note except for so.
a. sol 
El viaje en taxi desde el aeropuerto de Lima me costó unos 60 soles.The taxi ride from Lima's airport cost me about 60 soles.