Category:Octant

Oc"tant, n. Etym: [l. octans, -antis. fr. octo eight. See octave.]

1. (geom.)

Defn: the eighth part of a circle; an arc of 45 degrees.

2. (astron. & astrol.)

Defn: 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 9oº, but being itself the eighth Part of a circle. Cf. Sextant.

4. (math. & crystallog.)

Defn: one of the eight parts into which a space is divided by three Coördinate planes.