We take for granted today that there are standard measures for time, area, distance, and volume, but these were once very different from place to place. A standard agreed-upon hour of the day wasn’t even implemented until the mid-1800s. The avoirdupois system and the English system often used the names of body parts and vessels for measuring things, which gave us unusual and distinctly irregular names for lengths, depths, and weights.
Strangely enough, avoirdupois, which did not take its name from the human body—it originally meant "goods sold by weight"—has taken on a second, fleshly meaning over the centuries. Since the 1500s, avoirdupois has been used to mean "heaviness, especially personal weight."