Why Are Pounds Abbreviated Lbs?
The English “pound” comes from the old Latin word “pondo,” meaning “pound” as weight. The ancient Romans developed the pound as a measure to weigh money. The money was weighed on a “libra,” or scale. A pound of coins was called a “libra pondo,” or “a pound by weight.”
When the Roman measure reached England, merchants used the libra pondo to measure the weight of things such as wheat and meat. This was the Roman pound of 12 ounces, not the more modern one of 16.
In time, “pondo” became “pound,” and “libra” was shortened to “lb.” This became the abbreviation for “a pound by weight.” The libra is also why the symbol for the British pound is £—an L with a line through it. The Italian lira also used that symbol (with two lines through it), the word “lira” itself being a shortened version of libra.
There’s just no rhyme or reason as to why the word “pound” was taken from one Latin word but its abbreviation was taken from a different Latin word. It’s just one of the mysteries of language!