torchyoudaoicibaDictYouDict[torch 词源字典]
torch: [13] A torch is etymologically something ‘twisted’. The word comes via Old French torche from Vulgar Latin *torca, which was derived from the Latin verb torquēre ‘twist’ (source also of English torment, torture, etc). The notion underlying the word is of pieces of straw or similar material ‘twisted’ together and then dipped in some inflammable material. That is what it still denotes in American English, but in British English it has been reapplied to a battery-driven alternative to this.
=> torment, torque, torture[torch etymology, torch origin, 英语词源]
torch (n.)youdaoicibaDictYouDict
mid-13c., from Old French torche "torch," also "handful of straw" (for wiping or cleaning, hence French torcher "to wipe, wipe down"), originally "twisted thing," then "torch formed of twisted tow dipped in wax," probably from Vulgar Latin *torca, alteration of Late Latin torqua, from Latin torquere "to twist" (see torque (n.)).

In Britain, also applied to the battery-driven version (in U.S., a flashlight). To pass the torch is an ancient metaphor from the Greek torch-races (lampadedromia) where the goal was to reach the finish line with the torch still burning. Torch-bearer "leader of a cause" is from 1530s. Torch song is 1927 ("My Melancholy Baby," performed by Tommy Lyman, is said to have been the first so called), from carry a torch "suffer an unrequited love" (also 1927), Broadway slang, but the sense is obscure.
torch (v.)youdaoicibaDictYouDict
1819, "illuminate with a torch," from torch (n.). Meaning "set fire to" is from 1931. Related: Torched; torching.