one of nine actual or notional values of a variable dividing its distribution into ten groups with equal frequencies: the ninth decile is the value below which 90% of the population lie
See also percentile
b.
a tenth part of a distribution
Word origin
C17: from deca- + -ile
decile in American English
(ˈdɛsˌaɪl; ˈdɛsɪl)
noun
Statistics
any of the values which divide a frequency distribution into ten groups of equalfrequency; also, any of these groups