Which to use
“undo” is a verb and “UO” is a name - they look or sound alike but fill different roles in a sentence.
- #13,631
- “undo” frequency rank
- #39,629
- “UO” frequency rank
- 53260
- confusion score
Side-by-Side Comparison
| Feature | undo | UO |
|---|---|---|
| Definition | To reverse the effects of an action. | Initialism of University of Oregon |
Letter map: undo vs UO
Shared letters muted; letters that set undo and UO apart highlighted. Shared run: 2.
Part-of-speech tell for undo / UO
Our dataset has no pronunciation recorded for both members, so the reliable separator here is grammatical: undo is averb and UOaname. On the page they differ by 2 letter(s) in length. Our composite confusion score for this pair is 53260, derived from the frequency rank of both members and their visual similarity.
undo is recorded at frequency rank #13,631, classified as averb, pronounced /ʌnˈduː/. UO is at rank #39,629, tagged as aname.
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 53260, this pair ranks #150,420 of 530,003 scored English confusable pairs - roughly mid-pack for confusability.
Orthographic DNA of undo vs UO
Shared letters: ou. Private to "undo": dn. Private to "UO": -.
"undo" · 4 letters · shape VCCV · "UO" · 2 letters · shape VV
Known mistypes of this pair
- undo ← nudo · udno · unddo · unndo · unod
Frequently Asked Questions
Is swapping "undo" for "UO" ever safe?
In ordinary English text, does "undo" or "UO" show up more?
After this comparison
Done with this confusable. These links stay specific to "undo" and "UO".
- Full dictionary entry for "undo" with definition, IPA, and generated misspellings. Word entry
- Full dictionary entry for "UO" - compare definitions side by side with the headword page. Word entry
- This pair ranks #150,420 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
- "undo" and "UO" also get mixed up with nearby pairs, the highest-scored neighbour is "UAS vs UO". 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 #150,420 of 530,003 scored English pairs, corpus vintage 2026-09-03, not spelling advice.