A casement is a window that opens like a door: it has hinges at one side, and you push it out or pull it in. That is different from a sash window, which slides up and down.

A casement is a windowCasement是一種窗戶 that opens like a door打開方式像門一樣：it has hinges at one side一側有鉸鏈，and you push it out or pull it in你可以把它推出去或拉進來。That is different from a sash window這跟sash window（上下推拉窗）不同，which slides up and down那種窗戶是上下滑動的。

You meet the word in house descriptions and in older poems and stories, where someone opens a casement to the night and it sounds a little romantic. In everyday talk many people just say window, or opening window.

You meet the word in house descriptions and in older poems and stories你會在房屋介紹，還有比較老的詩和故事裡碰到這個字，where someone opens a casement to the night有人在這些地方對著夜晚打開casement，and it sounds a little romantic聽起來有點浪漫。In everyday talk在日常說法裡，many people just say window很多人就直接說window，or opening window或opening window。

There is also a family name Casement, from Irish, but that is a different word that only happens to look the same; the window does not come from that name. The window word is tied to an old sense of “case” as a frame or box — the window sits in a frame and swings on it.

There is also a family name Casement另外還有一個姓氏叫Casement，from Irish來自愛爾蘭語，but that is a different word that only happens to look the same但那是剛好長得一樣的另一個字；the window does not come from that name窗戶這個意思不是從那個姓氏來的。The window word is tied to an old sense of "case" as a frame or box窗戶這個用法跟case早期「框、盒子」的意思有關——the window sits in a frame and swings on it窗戶就是裝在框裡、繞著它擺動。