Which to use
“dud” is a noun and “dum” is an adjective - they look or sound alike but fill different roles in a sentence.
- #29,251
- “dud” frequency rank
- #23,517
- “dum” frequency rank
- 52768
- confusion score
Side-by-Side Comparison
| Feature | dud | dum |
|---|---|---|
| Definition | A device or machine that is useless because it does not work properly or has failed to work, such as a bomb, or explosive projectile. | cooked with steam |
Where the eye mixes dud and dum
Muted = shared; highlighted = the visual trap. They share 2 letters in sequence.
Visual trap between dud and dum
These two trip readers on the page rather than in the ear: dud is /dʌd/ while dum is /dʌm/. Spoken aloud the problem disappears. In writing it persists, because they differ by a single letter - d in “dud” becomes m in “dum”, and the parts of speech differ too (noun vs adjective), which is usually the fastest check. Our composite confusion score for this pair is 52768, derived from the frequency rank of both members and their visual similarity.
dud is recorded at frequency rank #29,251, classified as anoun, pronounced /dʌd/. dum is at rank #23,517, tagged as anadj, pronounced /dʌm/.
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 52768, this pair ranks #154,361 of 530,003 scored English confusable pairs - roughly mid-pack for confusability.
Orthographic DNA of dud vs dum
Shared letters: du. Private to "dud": -. Private to "dum": m.
"dud" · 3 letters · shape CVC · "dum" · 3 letters · shape CVC
Frequently Asked Questions
Do "dud" and "dum" mean the same thing in a sentence?
In ordinary English text, does "dud" or "dum" show up more?
What to do next
Pronunciation already separates them, if the page still looks alike, the dictionary links below settle it.
- Full dictionary entry for "dud" with definition, IPA, and generated misspellings. Word entry
- Full dictionary entry for "dum" - compare definitions side by side with the headword page. Word entry
- This pair ranks #154,361 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
- "dud" and "dum" also get mixed up with nearby pairs, the highest-scored neighbour is "dox vs dud". Nearby pair
Confusion rank #154,361 of 530,003 scored English pairs, corpus vintage 2026-09-03, not spelling advice.