Definition from Wiktionary, the free dictionary
See also décile
decile (plural deciles)
- (statistics) Any of the values in a series that divides the distribution of individuals in that series into ten groups of equal frequency.
- Although few people scored high marks, everyone did quite well—the lowest decile was over 50%.
- Any one of the ten subsets or groups so divided.
- Our school is in the top decile for exam results.
- (astrology) An aspect or position of two planets when they are distant from each other a tenth part of the zodiac.
Coordinate terms 
decile m (plural decili)
Related terms 
- (organic chemistry): decano