clew (n.)youdaoicibaDictYouDict[clew 词源字典]
"ball of thread or yarn," northern English and Scottish relic of Old English cliewen "sphere, ball, skein, ball of thread or yarn," probably from West Germanic *kleuwin (cognates: Old Saxon cleuwin, Dutch kluwen), from Proto-Germanic *kliwjo-, from PIE *gleu- "gather into a mass, conglomerate" (see clay).[clew etymology, clew origin, 英语词源]