hardness
/ˈhɑɹdnəs/
"hardness" is a 8-letter English headword indexed on PlainSpell.
The verdict
“hardness” is a moderately-common English word, ranked #23,292 in English word frequency and used as a noun.
- #23,292
- frequency rank, English
- 8
- letters
- 11
- tracked misspellings
- 5
- confusable pairs
According to Wiktionary data (CC BY-SA, analyzed May 6, 2026) - The quality of being hard.
Visual similarity to commonly confused words
How many letter changes separate each confused pair (Levenshtein distance, normalized).
Source: PlainSpell confusable corpus (Wiktionary, CC BY-SA).
| Property | Value |
|---|---|
| Headword | hardness |
| Language | English |
| Part of speech | Noun |
| IPA | /ˈhɑɹdnəs/ |
| Letters | 8 |
| Frequency rank | #23,292 |
| Misspellings tracked | 11 |
| Confusable pairs | 5 |
| Source | Wiktionary (kaikki.org) |
Where “hardness” sits in English frequency
Spelling & Dictionary Insight
The English entry for hardness is 8 letters long, classified as a noun, and transcribed in the International Phonetic Alphabet as /ˈhɑɹdnəs/. Corpus data places it at rank #23,292 in overall English word frequency, marking it as uncommon enough that many writers pause before typing it. Wiktionary records 7 distinct senses for this headword, so context determines which meaning a reader should apply.
Our generated misspelling index lists 11 likely wrong-spelling variants for hardness, with forms such as "ahrdness", "hadrness", and "harddness". Each variant is a distinct typo pattern an edit-distance generator flags, typically a doubled-consonant error, a silent-letter drop, or a vowel substitution. It also participates in 5 confusable-pair relationships, "harness", "harmless", "Harkness", and more, since the words sound or look close enough that writers reach for the wrong one mid-sentence.
Etymologically, the entry records: From Middle English hardness, hardnesse, from Old English heardnes, from heard + -nes, equivalent to hard + -ness. The correct English form is hardness, spelled H-A-R-D-N-E-S-S.
Definition
- 1The quality of being hard.
- 2An instance of this quality; hardship.
- 3The quantity of calcium carbonate dissolved in water, usually expressed in parts per million (ppm).
- 4The resistance to scratching, cutting, indentation or abrasion of a metal or other solid material.
- 5The penetrating ability of electromagnetic radiation, such as x-rays; generally, the shorter the wavelength, the harder and more penetrating the radiation.
- 6The measure of resistance to damage of a facility, equipment, installation, or telecommunications infrastructure when subjected to attack.
- 7A measure of how hard a material is.
Etymology
From Middle English hardness, hardnesse, from Old English heardnes, from heard + -nes, equivalent to hard + -ness.
Synonyms
Antonyms
This word in other languages
Common misspellings
Also misspelled as: ahrdness,hadrness,harddness,hardenss,hardnes,hardnness,hardnses,harndess,harrdness,hhardness,hradness
Misspelling Pattern Breakdown
How far each generated variant is from the correct spelling of hardness - measured in single-character edits (insert, delete, or substitute a letter). Larger bars are easier to catch; one-edit slips are the sneakiest.
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 “hardness”
The practical upshot for anyone who landed here from a spell-check.
- The one correct English spelling is H-A-R-D-N-E-S-S - every other letter order is a misspelling in standard orthography.
- Say it as /ˈhɑɹdnəs/ (IPA); tap the speaker on the pronunciation badge to hear it where audio exists.
- Don't mix it up with “harness” - see the side-by-side comparison. hardness vs harness
- 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.