wormyoudaoicibaDictYouDict[worm 词源字典]
worm: [OE] The ancestral meaning of worm appears to be ‘snake’; its application to smaller limbless creatures is a secondary development. It comes from a prehistoric Germanic *wurmiz, *wurmaz, which also produced German wurm, Dutch worm, and Danish orm ‘worm’ and Swedish orm ‘snake’. And this in turn went back to Indo-European *wrmi-, *wrmo- (source also of Latin vermis, from which English gets vermilion and vermin), a possible derivative of the base *wer- ‘turn, twist’ (source of English convert, reverse, etc) – in which case the worm would be etymologically the ‘twisting’ or ‘winding’ creature.
=> vermilion, vermin[worm etymology, worm origin, 英语词源]
worm (n.)youdaoicibaDictYouDict
Old English wurm, variant of wyrm "serpent, snake, dragon, reptile," also in later Old English "earthworm," from Proto-Germanic *wurmiz (cognates: Old Saxon, Old High German, German wurm, Old Frisian and Dutch worm, Old Norse ormr, Gothic waurms "serpent, worm"), from PIE *wrmi- "worm" (cognates: Greek rhomos, Latin vermis "worm," Old Russian vermie "insects," Lithuanian varmas "insect, gnat"), probably from root *wer- (3) "turn" (see versus).

The ancient category of these was much more extensive than the modern, scientific, one and included serpents, scorpions, maggots, and the supposed causes of certain diseases. For substitution of -o- for -u-, see come. As an insult meaning "abject, miserable person" it dates from Old English. Worms "any disease arising from the presence of parasitic worms" is from late Old English. Can of worms figurative for "difficult problem" is from 1951, from the literal can of worms a fisherman might bring with him, on the image of something all tangled up.
worm (v.)youdaoicibaDictYouDict
"to move like a worm," c. 1600, from worm (n.). In figurative senses attested from 1620s, suggesting patient, sinuous progress. Meaning "to free from worms" is from 1620s. Related: Wormed; worming.