Which to use
“undo” is a verb and “USO” is a noun - they look or sound alike but fill different roles in a sentence.
- #13,631
- “undo” frequency rank
- #35,573
- “USO” frequency rank
- 49204
- confusion score
Side-by-Side Comparison
| Feature | undo | USO |
|---|---|---|
| Definition | To reverse the effects of an action. | Unidentified submerged object or unidentified submarine object. |
Letter map: undo vs USO
Shared letters muted; letters that set undo and USO apart highlighted. Shared run: 2.
Part-of-speech tell for undo / USO
Our dataset has no pronunciation recorded for both members, so the reliable separator here is grammatical: undo is averb and USOanoun. On the page they differ by 1 letter(s) in length. Our composite confusion score for this pair is 49204, 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/. USO is at rank #35,573, tagged as anoun.
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 49204, this pair ranks #185,809 of 530,003 scored English confusable pairs - roughly mid-pack for confusability.
Orthographic DNA of undo vs USO
Shared letters: ou. Private to "undo": dn. Private to "USO": s.
"undo" · 4 letters · shape VCCV · "USO" · 3 letters · shape VCV
Known mistypes of this pair
- undo ← nudo · udno · unddo · unndo · unod
Frequently Asked Questions
Do "undo" and "USO" mean the same thing in a sentence?
Frequency check: "undo" vs "USO" - which ranks higher?
What to do next
Done with this confusable. These links stay specific to "undo" and "USO".
- Full dictionary entry for "undo" with definition, IPA, and generated misspellings. Word entry
- Full dictionary entry for "USO" - compare definitions side by side with the headword page. Word entry
- This pair ranks #185,809 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
- "undo" and "USO" also get mixed up with nearby pairs, the highest-scored neighbour is "UAS vs USO". 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 #185,809 of 530,003 scored English pairs, corpus vintage 2026-09-03, not spelling advice.