baityoudaoicibaDictYouDict[bait 词源字典]
bait: [13] Etymologically, the verb bait means ‘cause to bite’. It comes from Old Norse beita, a causative version of bita ‘bite’ (related to English bite). This took two semantic paths in English. In its aggressive mode, it meant literally ‘set dogs on someone’, and hence by figurative extension ‘harrass, persecute’. More peaceably, it signified ‘feed an animal’.

And this sense of ‘food provided’ is reflected in the noun bait, which comes partly from the verb, partly from the related Old Norse nouns beit ‘pasturage’ and beita ‘fish bait’. Old Norse beita was probably borrowed into Old French as beter, which with the prefix aproduced abeter, source of English abet [14], originally meaning ‘urge on, incite’.
=> abet, bite[bait etymology, bait origin, 英语词源]