octan

‖prop. n. pl. [ NL., fr. Gr. 'okta- (for 'oktw` eight) + &unr_;, &unr_;, male, man. ] (Bot.) A Linnaean class of plants, in which the flowers have eight stamens not united to one another or to the pistil. [ 1913 Webster ]

{ } a. (Bot.) Of or pertaining to the Octandria; having eight distinct stamens. [ 1913 Webster ]

n. [ See Octa- ] (Chem.) Any one of a group of metametric hydrocarbons (C8H18) of the methane (paraffin) series. The most important is a colorless, volatile, inflammable liquid, found in petroleum, and a constituent of gasoline or ligroin. [ 1913 Webster +PJC ]

a. [ L. octangulus eight-cornered; octo eight + angulus angle. ] Having eight angles; eight-angled. -- Oc*tan"gu*lar*ness, n. [1913 Webster]

n. [ L. octans, -antis. fr. octo eight. See Octave. ] 1. (Geom.) The eighth part of a circle; an arc of 45 degrees. [ 1913 Webster ]

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. [ 1913 Webster ]

3. An instrument for measuring angles (generally called a quadrant), having an arc which measures up to 9O°, but being itself the eighth part of a circle. Cf. Sextant. [ 1913 Webster ]

4. (Math. & Crystallog.) One of the eight parts into which a space is divided by three coordinate planes. [ 1913 Webster ]