One way to picture it: something bad falls on people by chance, and casualty is the name for the person it fell on — the one hurt or killed when the accident or the fighting swept through.
From the word’s history
Casualty goes back through casual to Latin cāsus "a fall, an event" (from cadere "to fall") — the same root as case. It first meant a chance happening; from there it narrowed to the people that chance happening fell upon.
casualty 經由 casual 上溯到拉丁文 cāsus（落下、發生的事，來自 cadere「掉落」），跟 case 同源。它原本指「偶然發生的事」，後來把焦點從「偶然發生的事」收窄到「這件事偶然落在誰身上」——也就是傷亡的那些人。這也解釋了為什麼 casual（隨意的）和 casualty（傷亡者）看起來奇怪地像親戚：兩邊都出自「碰巧掉下來」這個畫面。
Wiktionary（casualty / casual / Latin cāsus < cadere），與 Online Etymology Dictionary 一致
登入就可以看每一支怎麼連回核心畫面。
原始詞典資料8 筆記錄
以下是外部詞典記錄的用法，摘錄並精簡格式，我們還沒有寫成教學內容。上面的說明才是我們自己寫的；有些用法可能上面已經講過了。
casualtynoun/ˈkaʒʊ.əlti/
- 1
Something that happens by chance, especially an unfortunate event; an accident, a disaster.
- 1756, Samuel Johnson, “The Life of Sir Thomas Browne” in Thomas Browne, Christian Morals, 2nd edition, London: J. Payne, p. xx, The course of his education was like that of others, such as put him little in the way of extraordinary casualties.
- 2
A person suffering from injuries or who has been killed due to an accident or through an act of violence.
- 3
Specifically, a person who has been killed (not only injured) due to an accident or through an act of violence; a fatality.
- 4
governmentmilitarypoliticsA person in military service who becomes unavailable for duty, for any reason (notably death, injury, illness, capture, or desertion).
- 5
An incidental charge or payment.
- 6
Someone or something adversely affected by a decision, event or situation.
- Among recent casualties is the S.B.B.'s branch from Nyon to Divonne-les-Bains, just across the French frontier, closed to all traffic at the commencement of the winter service.
- Today, the pocket calculator is a dying product, a casualty of digitization, which has been relegated to the role of a graphic icon on phone and computer screens rather than an object in its own right, but back in the early 1970s, it was at the forefront of consumer technology.
- 7
obsoleteChance nature; randomness.
- The non-necessary [causes] follow; of which, saith Fuchsius, no art can be made, by reason of their uncertainty, casualty, and multitude […]
這個拼法也被記錄為下列字的變化形：
- casualty department
摘錄自 英文維基詞典 English Wiktionary，已精簡格式；依 CC BY-SA 4.0 授權使用，改動後的內容同樣以此授權提供。