quintile

 
Pronunciation: /ˈkwɪntɪl, -ʌɪl/

noun

  • 1 Statistics any of five equal groups into which a population can be divided according to the distribution of values of a particular variable.
  • each of the four values of the random variable which divide a population into quintiles.
  • 2 [mass noun] Astrology an aspect of 72° (one fifth of a circle).

Origin:

early 17th century: from Latin quintilis (mensis) 'fifth month, July', from quintus 'fifth'