octant

octant is defined in Webster's Unabridged Dictionary (1913) with 3 senses. The full text of each entry is reproduced verbatim below.

Definitions

  1. 1.(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.
  2. 2.An instrument for measuring angles (generally called a quadrant), having an arc which measures up to 9Oº, but being itself the eighth part of a circle. Cf. Sextant.
  3. 3.(Math. & Crystallog.) One of the eight parts into which a space is divided by three coördinate planes.

Source: Webster's Unabridged Dictionary, 1913 edition (public domain, via GCIDE / Project Gutenberg).

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