SSO
"sso" is a 3-letter English headword indexed on PlainSpell.
The verdict
“SSO” is uncommon English (frequency #57,094 among 54,294 “S” headwords), classed as a noun. The kind of spelling people second-guess.
- #57,094
- frequency rank, English
- 54,294
- “S” headwords
According to Wiktionary data (CC BY-SA, analyzed May 6, 2026) - Initialism of single sign-on.
| Property | Value |
|---|---|
| Headword | SSO |
| Language | English |
| Part of speech | Noun |
| Letters | 3 |
| Frequency rank | #57,094 |
| Misspellings tracked | 0 |
| Confusable pairs | 0 |
| Source | Wiktionary (kaikki.org) |
Where “SSO” sits in English frequency
Rare enough to double-check
SSO is uncommon English at frequency #57,094 among 54,294 “S” headwords, classed as anoun. Rarity is why readers land here mid-draft. 5 senses are on record.
Our edit-distance generator produced no likely misspellings for SSO, which points to an orthography that plays by predictable English rules. This entry stands alone in our confusable dataset, since its spelling is unusual enough that it doesn't cluster with a lookalike.
This headword's origin isn't recorded in our source data, so spelling patterns must be inferred from the word's phoneme-to-grapheme mapping rather than from a documented borrowing chain. The correct English form is SSO, spelled S-S-O.
Definition
- 1Initialism of single sign-on.
- 2Initialism of shared services organization.
- 3Initialism of sub-stellar object.
- 4Initialism of sun-synchronous orbit.
- 5Initialism of systematic social observation.
Definitions, pronunciation, and etymology for this entry are drawn from Wiktionary via the kaikki.org structured extract (CC BY-SA); frequency ordering uses the FrequencyWords open word-frequency list (2018 English corpus, MIT). See the methodology for how each field is sourced and updated.
Frequently Asked Questions
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Using “SSO”
The practical upshot for anyone who landed here from a spell-check.
- The one correct English spelling is S-S-O - every other letter order is a misspelling in standard orthography.
- Browse more English words and confusable pairs in the same reference. English words
Other uncommon English words near this rank
Data Source
Wiktionary (via kaikki.org), licensed under CC BY-SA & GFDL. Word ordering uses an open word-frequency list; misspelling variants are generated by edit-distance from the correct headword.