||Sa*git"ta (?), n. [L., an arrow.]
1. (Astron.) A small constellation north
of Aquila; the Arrow.
2. (Arch.) The keystone of an
arch. [R.] Gwilt.
3. (Geom.) 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.
[Obs.]
4. (Anat.) The larger of the two
otoliths, or ear bones, found in most fishes.
5. (Zoöl.) A genus of transparent,
free-swimming marine worms having lateral and caudal fins, and capable
of swimming rapidly. It is the type of the class
Chætognatha.