some of the quantiles which separate an ordered test population into eight equally numerous subsets.
A subset therefore acquired.
just like octant, 2.
In astronomy, same as octant, 2.
In statistics, a group containing one eighth of the total number of observations or of observed objects arranged upon a curve of frequency: usually marked off, as upper and lower octiles, to right and left of the abscissal points which bound the upper and lower quartiles.