a sitting room (or an enclosed porch) with large windows to let sunlight in freely
sun parlor in American English
noun
a porch or room with many windows exposed to sunshine; sun porch; solarium
Word origin
[1915–20, Amer.]This word is first recorded in the period 1915–20. Other words that entered Englishat around the same time include: camouflage, decoder, feedback, neorealism, takeout