The Latin phrase libra pondo referred to a pound by weight. English borrowed the word pound from pondo, but kept the abbreviation from libra, the Latin word for scales or balance. That is why lb and pound share no letters. The word libra also gave English the zodiac sign Libra, represented by scales, and the British pound symbol, an ornate L with a line through it that began as a scribal abbreviation for libra. The history of the hashtag symbol also appears to lead back to libra pondo, through scribes writing lb quickly in ways that gradually evolved toward the mark we recognize today.
Daniel notices the mismatch between lb and pound and wants to know why. What follows traces the two halves of the Latin phrase through their separate journeys, connects libra to the zodiac sign and the British currency symbol, and reveals the probable connection to the hashtag. The episode closes on Mom’s observation that language is archaeology in your mouth, and that every word carries the history of everywhere it has been.
Who’s talking
DanielHost & Chief Question-Asker
Daniel is nine. He asks the questions, refuses to accept easy answers, and picks every episode topic himself.
MomCo-host & Researcher
Mom does the digging - finding the sources, checking the claims, and translating them into something a nine-year-old will actually sit still for.
Things to remember
01
Lb comes from libra, the Latin word for scales. Pound comes from pondo, meaning by weight.
02
The two halves of the phrase libra pondo traveled different paths through history and never reunited.
03
Libra also gave us the zodiac sign and the British pound symbol, both connected to the idea of scales.
04
The hashtag symbol also appears to trace back to libra pondo through medieval scribal abbreviations.
“Language is archaeology in your mouth. Every word carries the history of everywhere it has been.”
DanielMom, I just noticed something. The abbreviation for pound is LB. But there is no L or B in the word pound. Where did LB even come from?
MomDaniel, it actually came from ancient Rome, 2,000 years ago, from a Latin phrase that got split in half on its way to English.
DanielWhat? A Latin phrase? How did it get to split in half?
MomThe word came from one part. The abbreviation came from the other.
DanielHmm, so what was the Latin phrase?
MomLibra Pondo. Two words. Libra, meaning scales or balance. Pondo, meaning by weight. Together, Libra Pondo, referred to a pound by weight.
DanielSo it was basically just the Roman way of saying pound.
MomExactly. And here is where the split happened. Over centuries, as the phrase traveled through languages into English, the word pound came from Pondo. But the abbreviation LB came from Libra.
DanielSo the word came from one half of the phrase, and the abbreviation came from the other half.
MomYes, they traveled down different paths through history. One survived in the word we say, and the other survived in the abbreviation we write.
DanielSo every time someone writes LB for pound, the word and the abbreviation are carrying two different pieces of the same Latin history.
MomTwo pieces of the same ancient phrase, surviving side by side more than 2,000 years later.
DanielWhat does Libra actually mean though? Like, why scales?
MomThe Libra was the Roman unit of weight, and the word itself meant balance or scales, because you weigh things by balancing them on a scale. The unit was named after the instrument used to measure it.
DanielSo Libra means both the scales and the thing you weigh on them.
MomAnd you know another place you have seen the word Libra?
DanielUm, the Zodiac sign?
MomYes, Libra, the seventh sign of the Zodiac, represented by a pair of scales. Same word, same meaning.
DanielSo the abbreviation for pound and the Zodiac sign for Libra come from the exact same Latin word.
MomAnd there is more. The symbol for the British pound, the currency, is also from Libra. That curly L with a line through it, the pound sign, started as just the letter L for Libra. Medieval writing conventions added a line to mark it as an abbreviation.
DanielSo pound for weight and that curly L for British money both come from the same Latin word.
MomAnd one more. The hashtag symbol. You know, the number sign, the hash mark. Its history also appears to lead back to Libra Pondo. Scribes used to write LB with a line across it to show it was an abbreviation. Over time, as people wrote it faster and faster, that symbol evolved toward the hash mark we recognize today.
DanielThe hashtag evolved from LB?
MomThat is where the symbol's history appears to lead. From an abbreviation rooted in ancient Rome to the symbol you use for hashtags today.
DanielSo this one, Latin word, Libra, connects the abbreviation LB, the British pound symbol, the zodiac sign Libra, and even, in a roundabout way, the hashtag.
MomAnd at the center of it all is a word a Roman might have used in a marketplace 2,000 years ago. Libra. Scales. Balance. Weight.
DanielLanguage is so much stranger than I thought.
MomIt is archaeology in your mouth. Every word carries the history of everywhere it has been. So Daniel, what is one thing you are taking with you today?
DanielI love it when you quiz me. Let's see if I can remember the important stuff. The abbreviation LB comes from the Latin word Libra, which means scales or balance. The word pound came from the other half of the phrase pondo. They traveled down different paths through history.
DanielAnd Libra also gave us the zodiac sign Libra, the British pound symbol, and, in a roundabout way, the hashtag.
MomThe next time you write a hashtag, remember, there is a little piece of ancient Rome hiding inside it.
DanielSo even hashtags have ancient history.
MomWelcome to etymology. Nothing is ever just a symbol anymore.
