Which to use
“diseased” is an adjective and “diseases” is a noun - they look or sound alike but fill different roles in a sentence.
- #25,037
- “diseased” frequency rank
- #3,873
- “diseases” frequency rank
- 28910
- confusion score
Side-by-Side Comparison
| Feature | diseased | diseases |
|---|---|---|
| Definition | Affected with or suffering from disease. | plural of disease |
Where the eye mixes diseased and diseases
Muted = shared; highlighted = the visual trap. They share 7 letters in sequence. diseased and diseases follow the identical consonant-vowel pattern (CVCVVCVC). Same shape at a glance is often the real trap, independent of shared letters.
Why the eye confuses diseased with diseases
These two trip readers on the page rather than in the ear: diseased is /dɪˈziːzd/ while diseases is /dɪˈziː.zɪz/. Spoken aloud the problem disappears. In writing it persists, because they differ by a single letter - d in “diseased” becomes s in “diseases”, and the parts of speech differ too (adjective vs noun), which is usually the fastest check. Our composite confusion score for this pair is 28910, derived from the frequency rank of both members and their visual similarity.
diseased is recorded at frequency rank #25,037, classified as anadj, pronounced /dɪˈziːzd/. diseases is at rank #3,873, tagged as anoun, pronounced /dɪˈziː.zɪz/.
Glosses for this pair are partially populated in our dataset, but the full side-by-side definitions above should still guide you to the right choice.
With a confusion score of 28910, this pair ranks #367,314 of 530,003 scored English confusable pairs - roughly mid-pack for confusability.
Orthographic DNA of diseased vs diseases
Shared letters: adeis. Private to "diseased": -. Private to "diseases": -.
"diseased" · 8 letters · shape CVCVVCVC · "diseases" · 8 letters · shape CVCVVCVC
Known mistypes of this pair
Frequently Asked Questions
Can "diseased" and "diseases" be used interchangeably?
In ordinary English text, does "diseased" or "diseases" show up more?
Useful next steps
Pronunciation already separates them, if the page still looks alike, the dictionary links below settle it.
- Full dictionary entry for "diseased" with definition, IPA, and generated misspellings. Word entry
- Full dictionary entry for "diseases" - compare definitions side by side with the headword page. Word entry
- This pair ranks #367,314 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
- "diseased" and "diseases" also get mixed up with nearby pairs, the highest-scored neighbour is "diseased vs disused". Nearby pair
- Recorded mistypes exist for at least one side of this pair, useful when a spell-checker or OCR lands on the wrong form. See mistypes
Confusion rank #367,314 of 530,003 scored English pairs, corpus vintage 2026-09-03, not spelling advice.