Crossword Genius

I brought in wall-painting, unusually large, back in well-lit room (8)

Ross

I believe the answer is:

solarium

I'm a little stuck... Click here to teach me more about this clue!

But I can't explain it at all! Could you help me understand?

(Other definitions for solarium that I've seen before include "Room for sunbathing" , "Room in which people can be exposed to sun or sun-lamps" , "Room where people can benefit from exposure to sunlight" , "Sunroom" , "conservatory?" .)

I've seen this clue in The Times.
Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.