solarium (n.)youdaoicibaDictYouDict[solarium 词源字典]
1891, "part of a house arranged to receive the sun's rays," earlier "sundial" (1842), from Latin solarium "sundial," also "a flat housetop," literally "that which is exposed to the sun," from sol "sun" (see sol).[solarium etymology, solarium origin, 英语词源]