Theory #1: People "kick the bucket" out from under themselves if they are committing suicide by hanging. Or if one person is hanging another person, they might kick the bucket out from under them. But this doesn't seem like a very good theory because if you were only standing on a bucket, you wouldn't fall very far, but I guess if the rope was short enough, and your feet didn't touch the floor, you would still strangle to death.
Theory #3: The best theory is that back in the 16th century, the word bucket also meant a beam or yoke that was used to hang or carry things. The French word trébuchet, which means "a balance," is likely where the English word bucket came from. When animals such as pigs were being killed, they were hung up by their feet, and then their throats got slit. While they were dying, they probably kicked the beam they were tied to, and so they "kicked the bucket." I don't like to think about this, but I'm just telling you, in the interest of linguistics, where this phrase might have come from.
A person who is punctilious likes to make sure that everything is done exactly right, even the smallest details. I guess this might be important if you are having a ceremony or a formal dinner or something, but it just seems kind of anal to me!
HOSTLER or OSTLER
That meaning is pretty much archaic, but the job of hostler got updated, and now it is somebody who takes care of trains, buses, and other such vehicles after their regular runs. The hostler moves the vehicles and large equipment, and does maintenance work on it.
I am not making this up. It really is a word, and what it means is "fear of long words." Hahahaha! But if you are a little scared by its length, you can just say sesquippedaliophobia, and that means the exact same thing!