rat-tail (n.)youdaoicibaDictYouDict[rat-tail 词源字典]
also rat's-tail, used since 16c. of conditions or devices held to resemble a rat's long, hairless tail in some sense, including "lank lock of hair" (1810); "end of a rope" (1867); from rat (n.) + tail (n.1).[rat-tail etymology, rat-tail origin, 英语词源]