octant

名词 octant:

1. a measuring instrument for measuring angles to a celestial body; similar to a sextant but with 45 degree calibration

oc.tant

n.（名词）
One eighth of a circle.
八分圆：圆的八分之一

A 45= arc.
45°弧
The area enclosed by two radii at a 45= angle and the intersected arc.
八分圆：一个被两条成45°角的半径及与之相交的弧所包围的区域
An instrument based on the principle of the sextant but employing only a 45= angle, used as an aid in navigation.
八分仪：以六分仪的规则为基础设计的一种仪器，但只采用45°角，用来帮助航海
Astronomy The position of a celestial body when it is separated from another by a 45= angle.
【天文学】 八分圆：一个天体当它成45°角与另一天体分离时所处的位置
One of eight parts into which three-dimensional space is divided by three usually perpendicular coordinate planes.
卦限：八个区之一，这八个区是由三个正交平分割三维空间而成

来源：
Latin oct3ns octant-
拉丁语 oct3ns octant-
from octô [eight] * see oktô(u)
源自 octô [八] *参见 oktô(u)

【引伸】
octan.tal