What does librae mean?
Librae is the plural form of libra, a traditional unit of weight corresponding to the pound. In historical, legal, and literary English, a writer might therefore refer to a quantity of “ten librae” rather than “ten pounds.” Its plural ending is Latin rather than the ordinary English -s, so the form can sound archaic or technical, although it is not restricted to any one English-speaking region. Librae also has a separate astronomical use as the Latin genitive of Libra, the zodiacal constellation: “the stars of Librae.” In that use it is normally capitalized and functions like the possessive form of the constellation’s name. Together, these uses connect the word with scales, measurement, commerce, and the night sky. The form is worth knowing chiefly because it appears in formal, historical, and specialist texts, where it preserves distinctions between older terminology and its modern English equivalents.
nounThe plural of libra, a traditional unit of weight corresponding to the pound. Librae is also the Latin genitive of the zodiacal constellation Libra.
- The plural of libra, denoting units of weight corresponding to the pound.
- The Latin genitive of Libra, the zodiacal constellation, as in astronomical nomenclature.
"The ledger records twelve librae of silver delivered to the merchant."
"The customs declaration listed twenty librae of imported tin."
"Astronomers mapped the brighter stars of Librae."
Librae is the standard Latin-style plural of libra and is used in formal, historical, literary, legal, and scientific contexts.
"The ledger records twelve librae of silver delivered to the merchant."
In an ancient marketplace, librae weighed on the scales; in the night sky, Librae still presides over a zodiac sign.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does librae come from?
Librae is the Latin plural of libra, meaning “balance” or “scales” and, by extension, a unit of weight. English borrowed libra as a unit and retained its Latin plural librae. In astronomical nomenclature, Librae is the Latin genitive of the constellation Libra, a usage distinct from the plural unit of weight.
Related word forms
How librae is actually used
Librae is uncommon in ordinary modern English and occurs chiefly in historical, legal, literary, or scientific contexts. Its astronomical use is normally capitalized as Librae and functions as the genitive of the constellation's name.
Easily confused with librae
Libra is the singular of libra and can denote an individual unit of weight, whereas librae normally denotes multiple such units.