One of the mysteries of the English language finally explained.
Statistics. Each of the seven values of a variate which divide a frequency distribution into eight groups each containing one eighth of the total population; (usually) specifically the first or seventh of these values.
Late 17th century (in an earlier sense). From classical Latin octo eight + -ile, after quartile [noun], quintile, sextile [noun], etc.
In this article we explore how to impress employers with a spot-on CV.