What does sagitta mean?
Sagitta is a specialized noun used chiefly in geometry for the height of an arc, particularly a circular arc. It denotes the perpendicular distance associated with an arc's rise above its chord and is used in calculations involving radii, chord lengths, and circular segments. The word has also been applied in entomology to a median vein of an insect's wing. Although it ultimately comes from the Latin word for “arrow,” sagitta is not generally used for an arrow in modern English. Instead, it survives as a learned term in technical writing, where its classical appearance distinguishes it from the more transparent expression “arc height.” Its relative rarity means that readers are most likely to encounter it in a mathematical or scientific context rather than in ordinary conversation.
The height of an arc, especially a circular arc; more specifically, the length of the perpendicular segment used to express an arc's rise from its chord.
"The calculator determines the sagitta before constructing the road's circular curve."
This is the most common modern use, though the term remains specialized.
A median vein running through an insect's wing.
"The specimen's wing venation included a prominent sagitta."
This sense is restricted to specialist entomological usage.
The conventional plural is sagittae; pronunciation may vary by speaker and institutional convention.
"The sagittae of the two arcs were calculated separately."
Latin sagitta means “arrow,” a fitting name for the height of an arc, which was traditionally represented by an arrow-shaped line.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of sagitta
The word comes from Latin sagitta, meaning “arrow.” Latin already used the word for the geometric height of an arc, probably because the relevant line segment was imagined as an arrow. The same Latin root also underlies sagittarius, the name of the archer and the traditional identification of one of the zodiac constellations.
How sagitta is actually used
The word is uncommon in modern English and is encountered mainly in geometry and specialist entomological writing. The plural is conventionally written sagittae.