soundness
noun
soundness is spelled S-O-U-N-D-N-E-S-S: 9 letters and 2 syllables. It appears about once in every 3 million words in written English, the 49,368th most frequent word form (wordfreq, 2021 data). As a noun, soundness means “The state or quality of being sound” (English Wiktionary, September 2026). The plural of soundness is soundnesses.
How many letters and syllables are in soundness?
| Letters | 9: S-O-U-N-D-N-E-S-S |
|---|---|
| Syllables | 2 (from its American pronunciation) |
| In writing | about once in every 3 million words; the 49,368th most frequent word form |
| Wrong spellings searched | none measured in search |
Sources: letters and syllables from the English Wiktionary's hyphenation or pronunciation and the CMU Pronouncing Dictionary; written frequency: wordfreq 3.1 (a 2021 snapshot of Wikipedia, subtitles, news, books, web text and social media).
How common is soundness?
Soundness appears about once in every 3 million words in written English, the 49,368th most frequent word form in the list.
Source: written frequency: wordfreq 3.1 (a 2021 snapshot of Wikipedia, subtitles, news, books, web text and social media).
How do you pronounce soundness?
Soundness has 2 syllables (counted from its American pronunciation in the CMU Pronouncing Dictionary).
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).
Forms of soundness
- soundnesses plural
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).
What does soundness mean?
The meanings the English Wiktionary records, quoted as written there (source below).
noun
- 1
The state or quality of being sound.
- 2
The result or product of being sound.
- 3
The property (of an argument) of not only being valid, but also of having true premises.
- 4
The 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.
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).
Soundness in Spanish, French, German and Portuguese
In the sense the property of logical theory:
| Language | Words |
|---|---|
| Spanish | completitud |
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract). Translations are Wiktionary's, by sense; a linked word has its own PlainSpell page.
Where does soundness come from?
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”).
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).