quartile

 
Pronunciation: /ˈkwɔːtʌɪl/

noun

Statistics
  • each of four equal groups into which a population can be divided according to the distribution of values of a particular variable: in the highest quartile, the mean age was 72
  • each of the three values of the random variable which divide a population into quartiles.

Origin:

late 19th century: from medieval Latin quartilis, from Latin quartus 'fourth'