sextant

名词 sextant:

1. a unit of angular distance equal to 60 degrees
2. a measuring instrument for measuring the angular distance between celestial objects; resembles an octant

1. A medieval instrument, now replaced by the sextant, that was once used to determine the altitude of the sun or other celestial bodies.
   星盘一种中世纪的仪器，曾用来测量太阳或其它天体的高度，现在已被六分仪取代