soundness
"soundness" is a 9-letter English headword indexed on PlainSpell.
The verdict
“soundness” is a moderately-common English word, ranked #49,642 in English word frequency and used as a noun.
- #49,642
- frequency rank, English
- 9
- letters
- 12
- tracked misspellings
According to Wiktionary data (CC BY-SA, analyzed May 6, 2026) - The state or quality of being sound.
| Property | Value |
|---|---|
| Headword | soundness |
| Language | English |
| Part of speech | Noun |
| Letters | 9 |
| Frequency rank | #49,642 |
| Misspellings tracked | 12 |
| Confusable pairs | 0 |
| Source | Wiktionary (kaikki.org) |
Where “soundness” sits in English frequency
Spelling & Dictionary Insight
The English entry for soundness is 9 letters long, classified as a noun. Corpus data places it at rank #49,642 in overall English word frequency, marking it as uncommon enough that many writers pause before typing it. Wiktionary records 4 distinct senses for this headword, so context determines which meaning a reader should apply.
Our generated misspelling index lists 12 likely wrong-spelling variants for soundness, with forms such as "osundness", "sonudness", and "soudnness". Every one of these variants traces to a single-character edit -- an added or dropped letter, a swapped consonant, or a vowel swap -- the kind of slip a spell-checker is built to catch. Our confusable-pair dataset has no match for it, since its spelling is unusual enough that it doesn't cluster with a lookalike.
Etymologically, the entry records: From Middle English soundenes, soundnes, from Old English *sundnes, *ġesundnes (attested in onsundnes), from Proto-West Germanic *sundnassī (“soundness, health”); equivalent to sound + -ness. Cognate with West Frisian sûnens (“soundness, health”), Middle Lo… The correct English form is soundness, spelled S-O-U-N-D-N-E-S-S.
Definition
- 1The state or quality of being sound.
- 2The result or product of being sound.
- 3The property (of an argument) of not only being valid, but also of having true premises.
- 4The property of a logical theory that whenever a wff is a theorem then it must also be valid. Symbolically, letting T represent a theory within logic L, this can be represented as the property that whenever T⊢φ is true, then T⊨φ must also be true, for any wff φ of logic L.
Etymology
From Middle English soundenes, soundnes, from Old English *sundnes, *ġesundnes (attested in onsundnes), from Proto-West Germanic *sundnassī (“soundness, health”); equivalent to sound + -ness. Cognate with West Frisian sûnens (“soundness, health”), Middle Low German suntnisse (“soundness, health”), Middle High German suntnisse (“soundness, health”), German Gesundnis (“health”).
This word in other languages
Common misspellings
Also misspelled as: osundness,sonudness,soudnness,sounddness,soundenss,soundnes,soundnness,soundnses,sounndess,sounndness,ssoundness,suondness
Misspelling Pattern Breakdown
How far each generated variant is from the correct spelling of soundness - expressed in single-character edits (insert, delete, or swap one letter). Bigger bars stand out at a glance; a one-edit slip is the hardest to catch.
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
How do you spell "soundness"?
What does "soundness" mean?
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Using “soundness”
The practical upshot for anyone who landed here from a spell-check.
- The one correct English spelling is S-O-U-N-D-N-E-S-S - every other letter order is a misspelling in standard orthography.
- Browse more English words and confusable pairs in the same reference. English words
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.