Definition of percentile in US English:

percentile

noun

Statistics
• 1Each of the 100 equal groups into which a population can be divided according to the distribution of values of a particular variable.

• ‘Table 1, which contains the simulation results, therefore displays percentiles of this distribution.’
• ‘An alternate method is presented, whereby data are mined from the laboratory information system for each analyte/analyzer combination and data are analyzed through comparison of population percentiles.’
• ‘We performed 10000 iterations and calculated the probability of obtaining the observed or a more extreme degree of homogeneity in the sign of effect size from the percentiles of the distribution of the results of the 10000 iterations.’
• ‘The terms tercile, quartile, quintile and decile should refer to the percentiles which divide the distribution into 3, 4, 5, or 10 equal parts, respectively.’
• ‘Comparison of population percentiles requires an adequate amount of data for statistical significance.’
1. 1.1 Each of the 99 intermediate values of a random variable that divide a frequency distribution into 100 groups.
‘the tenth percentile for weight’
• ‘Bars above histograms indicate the 1st, 5th, 95th, and 99th percentiles of the cumulative frequency distribution.’
• ‘While I was there I more than doubled some of the stamina records and scored in the top percentile of graduates in nearly every single academic exam.’
• ‘Comparing the top and bottom tenth percentiles, there was more than an eightfold difference in the proportion of patients monitored every 3 months and more than a twofold difference in the proportion of patients monitored every 6 months.’
• ‘While I am certain that there is a wide range of skill levels within the pool of available developers, that does not mean that those developers who are not in the top percentiles should be described as ‘substandard.’’
• ‘Then we divide the income of the household at the ninetieth percentile by the income of the household at the tenth percentile.’

percentile

/pərˈsɛnˌtaɪl//pərˈsenˌtīl/