織布機上的梭子
這是「來回」畫面最原始的樣子，後面幾個意思都保留了同一個動作。
loom shuttle · noun · B2
A pointed tool that carries thread back and forth across a loom.
梭子
核心畫面
Picture the small pointed tool on a being shot across the threads and back, over and over, always the same short route. That back-and-forth is the whole word. A bus doing the same short run between the hotel and the airport is doing what the shuttle does, and so is a spacecraft built to go up and come back and go again.
可以想成：織布機上那個尖尖的小工具，被「射」過經線再回來，一來一往，永遠是同一段短短的路線。這個「來回」就是整個字。…更多收起
可以想成：織布機上那個尖尖的小工具，被「射」過經線再回來，一來一往，永遠是同一段短短的路線。這個「來回」就是整個字。一輛在飯店和機場之間跑同一段路的巴士，做的就是梭子在做的事；一艘設計成上去、回來、再上去的太空船也是。From the word’s history
Shuttle is Middle English shitel, from Old English scytel 'a dart, arrow' (the root means 'to shoot'): the weaver's tool was named for being shot across the threads. The missile sense died out, but the back-and-forth image carried: shuttle trains from 1895, air services from 1942, spacecraft from 1969, and the verb 'move rapidly to and fro' from the 1540s.
shuttle 來自中古英文 shitel、古英文 scytel「飛鏢、箭」（字根的意思是「射」）：織布用的梭子之所以叫這個名字，是因為它被「射」過那排線。「飛鏢」的意思後來消失了，但「來回」的畫面留了下來：1895 年開始用在往返的火車上，1942 年用在航班上，1969 年用在太空船上；動詞「快速來回移動」則從 1540 年代就有了。
Online Etymology Dictionary (etymonline.com), entry "shuttle"
Three branches
來回跑同一段路的交通工具
把梭子的來回搬到交通上：固定的兩點之間，不斷往返。
shuttle bus, train · noun · A2
A bus, train, or plane that regularly travels back and forth between two places.
接駁車；穿梭巴士
來回移動（動詞）
同一個來回變成動作：自己往返，或把人載來載去。
travel back and forth · verb · B1
to travel often between two places, going back and forth again and again.
穿梭往返
原始詞典資料9 筆記錄
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。
shuttlenoun/ˈʃʌtəl/
- 1
businessmanufacturingtextilesA tool used to carry the woof back and forth between the warp threads on a loom.
- My dayes are ſwifter then a weauers ſhuttle, and are ſpent without hope.
- Like shuttles through the loom, so swiftly glide My feather'd hours, and all my hopes deride!.
- 2
The sliding thread holder in a sewing machine, which carries the lower thread through a loop of the upper thread, to make a lock stitch.
- 3
A transport service (such as a bus or train) that goes back and forth between two or more places.
- The shuttle bus runs to the airport on a half-hourly basis from the central station.
- And until December 2010 the northern stretch of the 'Extension' featured a charming side-show: the Chesham Shuttle. [...] But the people of Chesham moaned about the shuttle: the waiting room at Chalfont & Latimer was too hot, or too cold; there were leaves on the line. [...] On 12 Dec 2010 the shuttle ceased operations and Metropolitan trains began to terminate at both Amersham and Chesham.
- 4
Such a transport vehicle; a shuttle bus; a space shuttle.
- You're saying we take the parking shuttles, reinforce them with aluminum siding and then head to the gun store where our friend Andy plays some cowboy-movie, jump-on-the-wagon bullshit.
- 5
Any other item that moves repeatedly back and forth between two positions, possibly transporting something else with it between those points (such as, in chemistry, a molecular shuttle).
- 6
A shuttlecock.
- 7
A shutter, as for a channel for molten metal.
shuttleverb/ˈʃʌtəl/
- 1
To go or send back and forth between two places.
- On several occasions during the next several months my attempts to see the logs were met alternately with this denial of their existence or a denial of my right to see them. After being shuttled from station to headquarters and headquarters to station, I finally consulted with GCNs attorney, John Ward.
- 2
To transport by shuttle or by means of a shuttle service.
- Guests can be shuttled to and from the hotel for no extra cost.
- It may get even busier in town when a sleek train service called the Brightline debuts this summer, shuttling travelers between nearby West Palm Beach and Miami.
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。