- switch
[switch 词源字典]
- switch: [16] Switch originally denoted a ‘thin flexible twig’; it may have been borrowed from Middle Dutch swijch ‘bough, twig’. From the noun was derived the verb switch. This originally meant ‘beat with a switch’, but in the early 19th century the sense ‘bend or waggle to and fro like a flexible stick’ emerged, and this led on in the middle of the century via ‘divert’ to ‘turn off a train on to another track’ (the usage developed in American English, where the apparatus used for this is still known as a switch, as opposed to British English points).
By the end of the century this had broadened out to ‘connect or disconnect by pushing a contact to or fro’. The notion of ‘exchanging’ or ‘swopping’ did not emerge until as recently as the 1890s.
[switch etymology, switch origin, 英语词源] - turn-off (n.)
- "something that dampens one's spirits" recorded by 1971 (said to have been in use since 1968), from verbal phrase turn off "stop the flow of" (1850), from turn (v.) + off (adv.). Turn-off (n.) as "place where one road diverges from another" is from 1881.