bucket (n.) Look up bucket at Dictionary.com
mid-13c., from Anglo-French buquet "bucket, pail," from Old French buquet "bucket," which is from a 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").