Which to use
“rex” is a noun and “roo” is a verb - they look or sound alike but fill different roles in a sentence.
- #13,343
- “rex” frequency rank
- #13,787
- “roo” frequency rank
- 27130
- confusion score
Side-by-Side Comparison
| Feature | rex | roo |
|---|---|---|
| Definition | Rey, monarca. | Primera persona del singular (yo) del presente de indicativo de roer. |
Where the eye mixes rex and roo
Muted = shared; highlighted = the visual trap. They share 1 letter in sequence.
Visual trap between rex and roo
These two trip readers on the page rather than in the ear: rex is /ˈreːks/ while roo is [ˈroo]. Spoken aloud the problem disappears. In writing it persists, because they share most of their letters but differ in 2 positions, and the parts of speech differ too (noun vs verb), which is usually the fastest check. Our composite confusion score for this pair is 27130, derived from the frequency rank of both members and their visual similarity.
rex is recorded at frequency rank #13,343, classified as anoun, pronounced /ˈreːks/. roo is at rank #13,787, tagged as averb, pronounced [ˈroo].
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 27130, this pair ranks #228,316 of 323,831 scored Spanish confusable pairs - roughly mid-pack for confusability.
Orthographic DNA of rex vs roo
Shared letters: r. Private to "rex": ex. Private to "roo": o.
"rex" · 3 letters · shape CVC · "roo" · 3 letters · shape CVV
Frequently Asked Questions
Is swapping "rex" for "roo" ever safe?
Which is more common, "rex" or "roo"?
Useful next steps
Pronunciation already separates them, if the page still looks alike, the dictionary links below settle it.
- Full dictionary entry for "rex" with definition, IPA, and generated misspellings. Word entry
- Full dictionary entry for "roo" - compare definitions side by side with the headword page. Word entry
- This pair ranks #228,316 of 323,831 scored Spanish confusable pairs in this corpus vintage. Corpus statistics
- "rex" and "roo" also get mixed up with nearby pairs, the highest-scored neighbour is "rajo vs roo". Nearby pair
Confusion rank #228,316 of 323,831 scored Spanish pairs, corpus vintage 2026-09-03, not spelling advice.