bucketyoudaoicibaDictYouDict[bucket 词源字典]
bucket: [13] We first encounter bucket in the Anglo-Norman forms buket and buquet. It is not entirely clear where this came from, but it may be a derivative of Old English būc. The primary underlying sense of this was ‘something bulging or swelling’, and hence it meant not only ‘jug’ but also ‘belly’ (related are German bauch and Swedish buk ‘paunch’). It survived dialectally into modern English as bowk, meaning ‘milkpail’ and ‘large tub used in coal mines’. The bucket of ‘kick the bucket’ was originally a beam from from which slaughtered animals were hung; it is probably a separate word, from Old French buquet ‘balance’.
[bucket etymology, bucket origin, 英语词源]
bucket (n.)youdaoicibaDictYouDict
mid-13c., from Anglo-French buquet "bucket, pail," from Old French buquet "bucket," which is from Frankish or some other Germanic source, or a diminutive of cognate Old English buc "pitcher, bulging vessel," originally "belly" (buckets were formerly of leather as well as wood), both from West Germanic *buh- (cognates: Dutch buik, Old High German buh, German Bauch "belly"), possibly from a variant of PIE root *beu-, *bheu- "to grow, swell" (see bull (n.2)).

Kick the bucket "to die" (1785) perhaps is from unrelated Old French buquet "balance," a beam from which slaughtered animals were hung; perhaps reinforced by the notion of suicide by hanging after standing on an upturned bucket (but Farmer calls attention to bucket "a Norfolk term for a pulley").