Any arrowworm of the genus Sagitta

• Constellation between Cygnus and Aquila
• The Arrow constellation
• A small constellation in the northern hemisphere between Cygnus and Aquila and crossed by the Milky Way

Wikipedia Word definitions in Wikipedia
In geometry , the sagitta (sometimes abbreviated as sag ) of a circular arc is the distance from the center of the arc to the center of its base. It is used extensively in architecture when calculating the arc necessary to span a certain height and distance ...

Wiktionary Word definitions in Wiktionary
n. 1 The keystone of an arch. 2 (context geometry English) The distance from a point in a curve to the chord; also, the versed sine of an arc; so called from its resemblance to an arrow resting on the bow and string. 3 (context anatomy English) The larger ...