pigtail (n.)youdaoicibaDictYouDict[pigtail 词源字典]
1680s, "tobacco in a twisted roll," from pig (n.) + tail (n.). So called from resemblance. Meaning "braid of hair" is from 1753, when it was a fashion among soldiers and sailors. Applied variously to other objects or parts thought to resemble this in appearance.[pigtail etymology, pigtail origin, 英语词源]