英语词源字典 - 在线词源网站

filament (n.)[filament 词源字典]: "fine untwisted thread, separate fibril," 1590s, from Modern Latin filamentum, from Late Latin filare "to spin, draw out in a long line," from Latin filum "thread" (see file (v.1)). As the name of the incandescent element in a light-bulb, from 1881.[filament etymology, filament origin, 英语词源]
purl (v.1): "knit with inverted stitches," 1825; earlier "embroider with gold or silver thread" (1520s), probably from Middle English pirlyng "revolving, twisting," of unknown origin. The two senses usually are taken as one word, but even this is not certain. Klein suggests a source in Italian pirolare "to twirl," from pirolo "top." As a noun, from late 14c. as "bordering, frills," 1530s as "twisted thread of gold and silver."
twine (n.): "strong thread made from twisted strands," Old English twin "double thread," from Proto-Germanic *twiznaz "double thread, twisted thread" (cognates: Dutch twijn, Low German twern, German zwirn "twine, thread"), from the same root as twin (adj.).