jettisonyoudaoicibaDictYouDict[jettison 词源字典]
jettison: [15] Etymologically, to jettison something is to ‘throw’ it overboard. Like jet, as in ‘jet engine’, the word comes from Latin jactāre ‘throw’. The abstract noun derived from this was jactātiō, which entered English via Anglo-Norman getteson. It was used for the ‘action of throwing cargo overboard, especially in order to lighten a ship’, but it was not converted to its familiar modern role, as a verb, until as recently as the 19th century. The contracted form jetson, later jetsam, emerged in the 16th century, and later came to be used for such jettisoned material washed ashore.
=> jet, jctsam[jettison etymology, jettison origin, 英语词源]
jettison (v.)youdaoicibaDictYouDict
1848, from jettison (n.) "act of throwing overboard" to lighten a ship. This noun was an 18c. Marine Insurance writers' restoration of the earlier form and original sense of the 15c. word that had become jetsam, probably because jetsam had taken on a sense of "things cast overboard" and an unambiguous word was needed for "act of throwing overboard."

Middle English jetteson (n.) "act of throwing overboard" is from Anglo-French getteson, from Old French getaison "act of throwing (goods overboard)," especially to lighten a ship in distress, from Late Latin iactionem (nominative iactatio) "act of throwing," noun of action from past participle stem of iectare "toss about" (see jet (v.)). Related: Jettisoned.