reinyoudaoicibaDictYouDict[rein 词源字典]
rein: [13] A rein is etymologically something that ‘retains’. It goes back via Old French rene to Vulgar Latin *retina, a descendant of the Latin verb retinēre ‘hold back’, from which English gets retain and retinue. The rein for horses has no connection with the rein- of reindeer [14], incidentally; that comes from Old Norse hreinn ‘reindeer’, which may be of Lappish origin.
=> retain, retinue[rein etymology, rein origin, 英语词源]
rein (n.)youdaoicibaDictYouDict
c. 1300, "strap fastened to a bridle," from Old French rene, resne "reins, bridle strap, laces" (Modern French rêne), probably from Vulgar Latin *retina "a bond, check," back-formation from Latin retinere "hold back" (see retain). To give something free rein is originally of horses.
rein (v.)youdaoicibaDictYouDict
c. 1300, from rein (n.). Figurative extension "put a check on" first recorded 1580s. Related: Reined; reining. To rein up "halt" (1550s) is from the way to make a horse stop by pulling up on the reins.