Which to use
“rust” is a noun and “rusty” is an adjective - they look or sound alike but fill different roles in a sentence.
- #10,604
- “rust” frequency rank
- #12,855
- “rusty” frequency rank
- 23459
- confusion score
Side-by-Side Comparison
| Feature | rust | rusty |
|---|---|---|
| Definition | The deteriorated state of iron or steel as a result of moisture and oxidation; it consists mostly of iron(III) oxide (ferric oxide) and iron(II) oxide (ferrous oxide). | Marked or corroded by rust. |
Where the eye mixes rust and rusty
Muted = shared; highlighted = the visual trap. They share 4 letters in sequence.
Why the eye confuses rust with rusty
These two trip readers on the page rather than in the ear: rust is /ɹʌst/ while rusty is /ˈɹʌsti/. Spoken aloud the problem disappears. In writing it persists, because they differ by 1 extra letter(s) - “rust” sits inside “rusty”, and the parts of speech differ too (noun vs adjective), which is usually the fastest check. Our composite confusion score for this pair is 23459, derived from the frequency rank of both members and their visual similarity.
rust is recorded at frequency rank #10,604, classified as anoun, pronounced /ɹʌst/. rusty is at rank #12,855, tagged as anadj, pronounced /ˈɹʌsti/.
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 23459, this pair ranks #409,105 of 530,003 scored English confusable pairs - a relatively easy-to-tell-apart pair.
Orthographic DNA of rust vs rusty
Shared letters: rstu. Private to "rust": -. Private to "rusty": y.
"rust" · 4 letters · shape CVCC · "rusty" · 5 letters · shape CVCCV
Known mistypes of this pair
Frequently Asked Questions
Is swapping "rust" for "rusty" ever safe?
Frequency check: "rust" vs "rusty" - which ranks higher?
Useful next steps
Eye-level mix-up between "rust" and "rusty" is sorted above. Next: full entries or other pairs that share a letter shape.
- Full dictionary entry for "rust" with definition, IPA, and generated misspellings. Word entry
- Full dictionary entry for "rusty" - compare definitions side by side with the headword page. Word entry
- This pair ranks #409,105 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
- "rust" and "rusty" also get mixed up with nearby pairs, the highest-scored neighbour is "Rua vs rust". 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 #409,105 of 530,003 scored English pairs, corpus vintage 2026-09-03, not spelling advice.