the.com/orangery

means A glass-walled building, grander than a greenhouse, originally built to shelter orange and citrus trees through cold winters.

from The word arrives via French 'orangerie,' simply 'orange' plus the place-suffix '-erie' (a room or place for something, as in 'bakery' or 'rookery'). The trees themselves came north from the Mediterranean, and since oranges sulk and die below a certain temperature, European aristocrats from roughly the 1600s onward built heated, glazed halls just to keep them alive over winter — citrus-keeping became such a fashionable extravagance that the buildings for it eventually outgrew their fruit, becoming grand social spaces in their own right.