One way to hold this word: a title, printed on a 1977 film about a fight between good and evil far out in space. A title that famous stops staying on the poster — people reach for it whenever something real starts to look like that film, which is how a military defence programme ended up wearing the same two words.
Both uses go back to one place: the title of the 1977 science-fantasy film Star Wars.
兩個意思都回到同一個起點：1977 年那部科幻電影的片名 Star Wars。電影是本尊，軍事計畫的用法是借來的外號。
Wiktionary entry supplied in packet (source_ref kaikki:3f6f69a190036ae4:679840328), etymology_text: 'From the original name of the science fantasy motion picture Star Wars (1977).'
Two branches
電影本身，以及整個系列
這就是核心：一個作品的名字，先指那部片，再擴大指整個系列。
noun · B1
A US science-fiction film made by George Lucas in 1977, and the series of films and stories that grew out of it, set in a faraway part of the universe where a good side fights an evil side with the help of a magic power called the Force.
星際大戰
借片名當外號：一個軍事防禦計畫
名字離開了作品，被貼到現實裡的一個計畫上。指的不是內容相同，而是「聽起來就像那部片」。
noun · C1
An informal name for the Strategic Defense Initiative, or SDI, a United States military defence programme. The nickname is borrowed from the title of the film.
星戰計畫
以下是外部詞典記錄的用法，原文照列，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。
Star Warsname[ˈstɑː(ɹ)ˈwɔː(ɹ)z]
An American epic space opera franchise centered on a film series created by George Lucas in a setting where futuristic technology coexists with a semisentient form of magic or religion called the Force.
informalgovernmentmilitarypoliticsThe United States Strategic Defense Initiative.
資料來源：英文維基詞典 English Wiktionary（CC BY-SA 4.0）。 原文照列，未經改寫。