Select the most appropriate one-word substitution for the given group of words. 

A place for sunlight to enter where one can sunbath 

Solarium

The most appropriate one-word substitution for "a place for sunlight to enter where one can sunbath" is solarium.

• Greenhouse is a building or structure with glass walls and roof that is used to grow plants.
• Asteroid is a small, rocky body that orbits the Sun.
• Solar-system is a group of planets, moons, asteroids, comets, and dust that orbit the Sun.

The word solarium comes from the Latin words "sol," meaning "sun," and "-arium," meaning "place of." A solarium is a room or area that is specially designed to let in sunlight. Solariums are often used for sunbathing, and they can also be used for relaxation and meditation.