nonant

Meanings

1. One of the nine sections made by dividing an area with two perpendicular sets of two parallel lines.
2. One ninth of a circle or disc; a sector with an angle of 40°.
3. A theoretical measuring device with a graduated arc of 40° used in locating an altitude.

Etymology

Borrowed from Latin nōnum, accusative singular of nōnus (“ninth part of something, ninth”), with -ant from similar Latin words such as octans.