Etymology

There are many theories as to where this idiom comes from, but the OED (Oxford English Dictionary) discusses the following:

• A person standing on a pail or bucket with their head in a slip noose would kick the bucket so as to commit suicide. The OED, however, says this is mainly speculative;
• The OED describes as more plausible the archaic use of "bucket" as a beam from which a pig is hung by its feet prior to being slaughtered. To kick the bucket, then, originally signified the pig's death throes;

Another explanation is given by a Roman Catholic Bishop, The Right Reverend Abbot Horne, F.S.A. He records on page 6 of his booklet "Relics of Popery" Catholic Truth Society London, 1949, the following:

• "After death, when a body had been laid out, ... and ... the holy-water bucket was brought from the church and put at the feet of the corpse. When friend came to pray... they would sprinkle the body with holy water .. it is easy to see how such a saying as " kicking the bucket " came about. Many other explanations of this saying have been given by persons who are unacquainted with Catholic custom"

Pronunciation

• (Received Pronunciation, US) IPA^(key): /ˈkɪk ðə ˈbʌkɪt/