pleonasm (n.)youdaoicibaDictYouDict[pleonasm 词源字典]
"redundancy in words," 1580s, from Late Latin pleonasmus, from Greek pleonasmos, from pleonazein "to be more than enough, to be superfluous," in grammatical use, "to add superfluously," from comb. form of pleon "more" (see pleio-).[pleonasm etymology, pleonasm origin, 英语词源]