Q: I was talking to my wife about a post in which you say “lb.” is short for “pound” because the abbreviation comes from the Latin libra. My wife wondered if libra is also the source of the Spanish word for book.
A: As we say in our posting, that English abbreviation for pound comes from the Latin libra. However, libra is not the source of libro, the Spanish word for book.
In classical Latin, libra has a couple of meanings. It means a balance or a set of scales, and it’s also the word for a specific weight—the Roman pound (12 ounces).
Traces of both meanings linger today.
As we say in that posting, we use “lb.,” an abbreviation of libra, as a modern English term for “pound.”
The name “Libra” has also been given to a constellation resembling scales, as well as to the corresponding sign of the zodiac (symbolized by a set of scales). (We had a posting yesterday about whether one weighs oneself on the “scale” or the “scales.”)
But don’t confuse libra with liber, the Latin source of the Spanish libro as well as some book-related terms in English.
In Latin, there are several different words that are spelled liber and that are derived from one or the other of two unrelated ancient roots.
The Oxford English Dictionary says the Roman use of liber for “book” is thought to come from the Latin word for “bark” (liber), “the bark of trees having, according to Roman tradition, been used in early times as a writing material.”
The “book” and “bark” senses of liber are ultimately derived from a reconstructed Indo-European base for leaf, loubh- or lubh-, according to the Chambers Dictionary of Etymology. (The American Heritage Dictionary of Indo-European Roots spells it leup-.)
English words derived from this liber include “library,” “libretto,” and “libel” (from libellus, a small book or pamphlet). Some related words for book in other languages are libro (Spanish and Italian), livre (French), and livro (Portuguese).
Another Latin word spelled liber means “free” and comes from the same prehistoric root as the Greek word for “free,” eleutheros. That root is leudh-, according to American Heritage, which says its “precise semantic development is obscure.”
The Latin liber for “free” has given us such English words as “liberty,” “liberal,” “liberate,” and “libertine.”
To sum things up, the English abbreviation of “pound” isn’t related to the Spanish word for “book,” despite the similarity of their Latin roots, though etymology can sometimes make for heavy reading.
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