flounder (v.)youdaoicibaDictYouDict[flounder 词源字典]
"struggle awkwardly and impotently," especially when hampered somehow, 1590s, of uncertain origin, perhaps an alteration of founder (q.v.), influenced by Dutch flodderen "to flop about," or native verbs in fl- expressing clumsy motion. Figurative use is from 1680s. Related: Floundered; floundering. As a noun, "act of struggling," by 1867.[flounder etymology, flounder origin, 英语词源]
flounder (n.)youdaoicibaDictYouDict
"flatfish," c. 1300, from Anglo-French floundre, Old North French flondre, from Old Norse flydhra, from Proto-Germanic *flunthrjo (cognates: Middle Low German vlundere, Danish flynder, Old Swedish flundra "flatfish"), suffixed and nasalized form of PIE *plat- "to spread" (cognate: Greek platys "flat, wide, broad;" see plaice (n.)).