## English

### Etymology

hexa- +‎ decile or hexadeca- +‎ -ile.

### Noun

1. Any of the quantiles which divide an ordered sample population into sixteen equally numerous subsets; a subset thus obtained.
• 1974, Robert George Gough, Improving the Quality of and Aggregating Opinions Expressed as Subjective Probability Distributions [unpublished Ph.D. dissertation], Stanford, Calif.: Stanford University, →OCLC, page 16:
The assessor can then be asked to successively divide an interval into equally likely segments yielding the octiles (X.125, X.875), hexadeciles (X.0625, X.9375), etc., etc.
• 2002 July 20, “Defining Quartiles”, in Ask Dr. Math, The Math Forum, Goodwin College of Professional Studies, Drexel University[1], archived from the original on 6 September 2015:
With each of the above methods, the quartile values are always either one of the data points, or exactly half way between two data points. Those methods involve only simple arithmetic and are easily extendable to octiles (eighths), hexadeciles (sixteenths), etc. They are not, however, extendable to quintiles (fifths) or percentiles (hundredths), etc. Furthermore, they tend to have a high bias. (That is, the quartile values calculated on subsets of the data set tend to vary more, and are not good predictors of the quartile values of the entire data set.)
2. The aspect or position of any two celestial bodies separated by 22.5° (that is, 360° divided by 16) as they appear to an observer on earth.
• 1683, George Wharton, “Of the Planetary Aspects, both Old and New, their Characters, and Æquations”, in John Gadbury, editor, The Works of that Late Most Excellent Philosopher and Astronomer, Sir George Wharton, Bar[onet]. Collected into One Entire Volume, London: Printed by H. H. for John Leigh, at Stationers Hall, →OCLC, page 92:
But becauſe ſome Aſpects are more Effectual than others, therefore they are (reſpectu graduum, Scientiæ and Congruentiæ, necnon Efficacitatus) thus to be Diſposed: viz. ☌. ☍. ◻. △. ⚹. SS. Q. Bq. Vc. Dec. Td. Sq. SSq. whereunto are added (as in the laſt and loweſt degree of Dignity and Efficacy) the Quindecile, Hexadecile, Vigintile, and the Icoſiteſſeragonall, (or figure of 24 ſides), which are only considered in Venus and Mercury with the Sun.

#### Usage notes

Not to be confused with hexadecyl.