English
kurtosis
Kurtosis comes from Ancient Greek κύρτωσις ‘a bulging, convexity’, and goes back to κυρτός.
- Ancient Greekc. 800–300 BCEκυρτόςkurtós‘bulging, convex’
- Ancient Greek, derivedc. 800–300 BCEκύρτωσιςkúrtōsis‘a bulging, convexity’
- Englishtodaykurtosis
attested reconstructed ? uncertain or disputed
Lineage
- Ancient Greekc. 800–300 BCEκυρτόςkurtós‘bulging, convex’
- Ancient Greek, derivedc. 800–300 BCEκύρτωσιςkúrtōsis‘a bulging, convexity’
- Englishtodaykurtosis
The story
Coined by English mathematician, biometrician, and eugenicist Karl Pearson c. 1895 (published 1899 in "On certain Properties of the Hypergeometrical Series, and so on the fitting of such series to Observation Polygons in the Theory of Chance", Phil.
Every English word from Ancient Greek κυρτός
Today it means
noun A measure of "heaviness of the tails" of a probability distribution, defined as the fourth cumulant divided by the square of the variance of the probability distribution.
Language periods are conventional ranges, not dates for this word.
Etymograph / Ancient Greek κυρτός / kurtosis