quartile

Etymology

From Middle French quartil, from Medieval Latin quartilus.

noun

1. (statistics) Any of the three points that divide an ordered distribution into four parts, each containing a quarter of the population.
2. (statistics) Any one of the four groups so divided.
   This school is ranked in the first quartile.
   The Department for Transport's National Travel Survey shows that workers in the lowest income quartile are twice as likely to use public transport. July 28 2021, Paul Clifton, “Network News: Confusion and dissent over face mask requirements: Reaction to the Guidance: British Safety Council”, in RAIL, number 936, page 6