rubivsrustWhat's the difference?

Which to use

“rubi” and “rust” are a confusable Portuguese pair: similar on the page, but distinct in meaning, check the gloss before you choose.

#19,840
“rubi” frequency rank
#46,045
“rust” frequency rank
65885
confusion score

Side-by-Side Comparison

Feature rubi rust
Definition pedra preciosa e transparente, de cor vermelha ferrugem

Where the eye mixes rubi and rust

Muted = shared; highlighted = the visual trap. They share 2 letters in sequence.

4 ch
rubi
4 ch
rust

Why the eye confuses rubi with rust

A purely visual mix-up. rubi (/Ru.ˈbi/) and rust (/ɹʌst/) are said differently, so reading them aloud is the quickest way to catch the wrong one. On the page they stay close: they share most of their letters but differ in 2 positions. Our composite confusion score for this pair is 65885, derived from the frequency rank of both members and their visual similarity.

rubi is recorded at frequency rank #19,840, classified as anoun, pronounced /Ru.ˈbi/. rust is at rank #46,045, tagged as anoun, pronounced /ɹʌst/.

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 65885, this pair ranks #5,198 of 75,631 scored Portuguese confusable pairs - among the most confusable pairs.

Orthographic DNA of rubi vs rust

Shared letters: ru. Private to "rubi": bi. Private to "rust": st.

"rubi" · 4 letters · shape CVCV  ·  "rust" · 4 letters · shape CVCC

Known mistypes of this pair

  • rubirbui · rrubi · rubbi · ruib · urbi
  • rustrrust · rsut · russt · rustt · ruts · urst

Frequently Asked Questions

Is swapping "rubi" for "rust" ever safe?
No. They are said differently (/Ru.ˈbi/ versus /ɹʌst/) and carry different meanings; reading the sentence aloud is usually enough to catch the wrong one.
In ordinary Portuguese text, does "rubi" or "rust" show up more?
"rubi" is the more common of the two: it sits at frequency rank #19,840 in our Portuguese list, against #46,045 for "rust". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

What to do next

Pronunciation already separates them, if the page still looks alike, the dictionary links below settle it.

  • Full dictionary entry for "rubi" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "rust" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #5,198 of 75,631 scored Portuguese confusable pairs in this corpus vintage. Corpus statistics
  • "rubi" and "rust" also get mixed up with nearby pairs, the highest-scored neighbour is "ruma 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 #5,198 of 75,631 scored Portuguese pairs, corpus vintage 2026-09-03, not spelling advice.

Source: Wiktionary (via kaikki.org) Structured Wiktionary extract

Source: FrequencyWords open word-frequency list