standard deviation
"standard-deviation" is a 17-letter English headword indexed on PlainSpell.
The verdict
“standard deviation” is uncommon English (outside the top frequency list), classed as a noun. The kind of spelling people second-guess.
- Unranked
- below top-frequency English
- 18
- letters
According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - A measure of how spread out data values are around the mean, defined as the square root of the variance. Represented with the Greek letter σ (sigma).
Corpus desk
Index EN-standard-deviation · standard deviation · English
standard deviation · unranked · 0 variants · 0 confusables
- FREQ-UNRANKED Unranked
- LEN-MEGA 18 letters
- VOW-7 7 vowels
- CONFUS-0 No pairs
- VAR-0 0 variants
- BOOK-THIN "S" thin
- PHOTO-UNK Peer pending
Read with this headword: Spelling guide for this pattern
Desk codes from Wiktionary headword shape, FrequencyWords rank tier, confusable-pair count, generated misspelling depth, letter-cohort book size, and photo-finish peer. Not a difficulty grade.
| Property | Value |
|---|---|
| Headword | standard deviation |
| Language | English |
| Part of speech | Noun |
| Letters | 18 |
| Misspellings tracked | 0 |
| Confusable pairs | 0 |
| Source | Wiktionary (kaikki.org) |
Long-tail rank of “standard deviation” in English
Rare enough to double-check
standard deviation is uncommon English outside the top frequency list, classed as anoun. Rarity is why readers land here mid-draft. Gloss: "A measure of how spread out data values are around the mean, defined as the square root of the variance. Represented with the Greek letter σ (sigma).".
No misspelling variants are generated for standard deviation in our index, which points to an orthography that plays by predictable English rules. Our confusable-pair dataset has no match for it, a sign it's visually distinctive enough not to be mixed up with another word.
Etymologically, the entry records: Coined by English mathematician, biometrician, and eugenicist Karl Pearson in 1894 in his paper "On the dissection of asymmetrical frequency curves". The correct English form is standard deviation, spelled S-T-A-N-D-A-R-D- -D-E-V-I-A-T-I-O-N.
Definition
- 1A measure of how spread out data values are around the mean, defined as the square root of the variance. Represented with the Greek letter σ (sigma).
Etymology
Coined by English mathematician, biometrician, and eugenicist Karl Pearson in 1894 in his paper "On the dissection of asymmetrical frequency curves".
Synonyms
This word in other languages
Definitions, pronunciation, and etymology for this entry are drawn from Wiktionary via the kaikki.org structured extract (CC BY-SA). See the methodology for how each field is sourced and updated.