French window

"Fahrenheit 451" を読んでいます。 今年の１月に読んだ小説 "WILDERNESS" に出てきた "Venetian blind" を思い出させる表現 "French windows" が次ぎの様に出てきました。
The room was cold but nonetheless he felt he could not breathe. He did not wish to open the drapes and open the French windows, for he did not want the moon to come into the room. So, with the feeling of a man who will die in the next hour for lack of air, he felt his way toward his open, separte, and therefore cold bed.
早速  "French window" を調べます。
・Merriam-Webster's Learner's Dictionary: a pair of casement windows that reaches to the floor, opens in the middle, and is placed in an exterior wall
・Wikipedia: French doors are derived from an original French design called the casement door. It is a door with lites where all or some panels would be in a casement door. A French door traditionally has a moulded panel at the bottom of the door. Called a French window when used in pairs as double-leaved doors with large glass panels in each door leaf, and in which the doors may swing out (most typical) as well as in.