2. (Astron. & Astrol.) The position or aspect of a heavenly
body, as the moon or a planet, when half way between
conjunction, or opposition, and quadrature, or distant
from another body 45 degrees.
3. An instrument for measuring angles (generally called a
quadrant), having an arc which measures up to 9O[deg], but
being itself the eighth part of a circle. Cf. {Sextant}.
4. (Math. & Crystallog.) One of the eight parts into which a
space is divided by three co["o]rdinate planes.