Which to use
“undo” is a verb and “Unix” is a name - they look or sound alike but fill different roles in a sentence.
- #13,631
- “undo” frequency rank
- #19,495
- “Unix” frequency rank
- 33126
- confusion score
Side-by-Side Comparison
| Feature | undo | Unix |
|---|---|---|
| Definition | To reverse the effects of an action. | An operating system that shares the original source code by Dennis Ritchie and Ken Thompson. |
Where the eye mixes undo and Unix
Muted = shared; highlighted = the visual trap. They share 2 letters in sequence.
Look-alike desk: undo vs Unix
These two trip readers on the page rather than in the ear: undo is /ʌnˈduː/ while Unix is /ˈjuː.nɪks/. 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 (verb vs name), which is usually the fastest check. Our composite confusion score for this pair is 33126, 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/. Unix is at rank #19,495, tagged as aname, pronounced /ˈjuː.nɪks/.
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 33126, this pair ranks #332,056 of 530,003 scored English confusable pairs - roughly mid-pack for confusability.
Orthographic DNA of undo vs Unix
Shared letters: nu. Private to "undo": do. Private to "Unix": ix.
"undo" · 4 letters · shape VCCV · "Unix" · 4 letters · shape VCVC
Known mistypes of this pair
Frequently Asked Questions
Can "undo" and "Unix" be used interchangeably?
In ordinary English text, does "undo" or "Unix" show up more?
What to do next
Visual near-miss handled. Browse the word pages or a neighbour when the next look-alike shows up.
- Full dictionary entry for "undo" with definition, IPA, and generated misspellings. Word entry
- Full dictionary entry for "Unix" - compare definitions side by side with the headword page. Word entry
- This pair ranks #332,056 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
- "undo" and "Unix" also get mixed up with nearby pairs, the highest-scored neighbour is "Unix vs uric". 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 #332,056 of 530,003 scored English pairs, corpus vintage 2026-09-03, not spelling advice.