pentile noun 2verb 1forms 3 noun2 •Any one of the five groups.Her income placed her in the lowest pentile of the income distribution. •Any of the four points that divide an ordered distribution into five parts, each containing a fifth (20%) of the population. Used commonly for income distributions. verb1 •To divide into pentiles.Apply pentiling to streamflows at all hydro plant locations from American Falls to Brownlee inflow (i.e. years comprising a pentile at Brownlee are those comprising the pentile at all locations) — 2005 formspentiled · pentiling · pentiles