pis aller (n.)youdaoicibaDictYouDict[pis aller 词源字典]
"last resource, what one would do at the worst," 1670s, French, literally "to go worse," from pis "worse," from Latin peius, neuter of peior "worse" (see pejorative) + aller "to go."[pis aller etymology, pis aller origin, 英语词源]