noun · 2 senses · updated from the 2026-07-25 local source snapshot
Definitions and examples are grouped by meaning. Pronunciation, history, word forms, translations, descendants, synonyms, antonyms, derived terms, and related words appear whenever the source provides them.
Sound
Pronunciation
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kər-tō′sĭs
Received-Pronunciation:/kəˈtəʊ.sɪs/
Received-Pronunciation:/ˌkɜːˈtəʊ.sɪs/
Canada, General-American:/kɚˈtoʊ.sɪs/
Canada, General-American:/ˌkɝˈtoʊ.sɪs/
Australian:/kəˈtəʉ.sɪs/
Australian:/kəˈtɐʉ.sɪs/
Australian:/ˌkɜːˈtəʉ.sɪs/
Australian:/ˌkɜːˈtɐʉ.sɪs/
1
noun
Meaning 1
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.
Definition source: English Wiktionary via Wiktextract
Usage: countable, uncountable
Topics: mathematics, sciences, statistics
No example sentence was provided for this meaning.
Meaning relationships
Synonyms: none provided
Antonyms: none provided
2
noun
Meaning 2
Excess kurtosis: the difference between a given distribution's kurtosis and the kurtosis of a normal distribution.
Definition source: English Wiktionary via Wiktextract
Usage: countable, uncountable
Topics: mathematics, sciences, statistics
No example sentence was provided for this meaning.
Meaning relationships
Synonyms: none provided
Antonyms: none provided
History
Etymology
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. Mag.). From Ancient Greek κύρτωσις (kúrtōsis, “a bulging, convexity”), from κυρτός (kurtós, “bulging, convex”).
Across languages
Translations
16 source translations are retained for this English entry.
Arabic:
تَفَرْطُح
(tafarṭuḥ)
— measure of "tail heaviness"
Catalan:
curtosi
— measure of "tail heaviness"
Chinese Mandarin:
峰度
(fēngdù)
— measure of "tail heaviness"
Czech:
špičatost
— measure of "tail heaviness"
Czech:
koeficient špičatosti
— measure of "tail heaviness"
Finnish:
huipukkuus
— measure of "tail heaviness"
Finnish:
kurtoosi
— measure of "tail heaviness"
French:
kurtosis
— measure of "tail heaviness"
French:
coefficient d'aplatissement
— measure of "tail heaviness"
German:
Kurtosis
— measure of "tail heaviness"
German:
Wölbung
— measure of "tail heaviness"
Portuguese:
curtose
— measure of "tail heaviness"
Russian:
эксце́сс
(ekscéss)
— measure of "tail heaviness"
Russian:
коэффицие́нт эксце́сса
(koefficijént ekscéssa)
— measure of "tail heaviness"