duckvsdudWhich spelling fits?

Quick tell: duck is a verb, dud is a noun, so they fill different roles in a sentence.

Which to use

“duck” is a verb and “dud” is a noun - they look or sound alike but fill different roles in a sentence.

#5,031
“duck” frequency rank
#29,251
“dud” frequency rank
34282
confusion score

Side-by-Side Comparison

Feature duck dud
Definition To quickly lower (the head or body), often in order to prevent it from being struck by something. 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.

Where the eye mixes duck and dud

Muted = shared; highlighted = the visual trap. They share 2 letters in sequence.

4 ch
duck
3 ch
dud

Why the eye confuses duck with dud

These two trip readers on the page rather than in the ear: duck is /dʌk/ while dud is /dʌd/. Spoken aloud the problem disappears. In writing it persists, because they differ by 1 letter(s) in length, and the parts of speech differ too (verb vs noun), which is usually the fastest check. Our composite confusion score for this pair is 34282, derived from the frequency rank of both members and their visual similarity.

duck is recorded at frequency rank #5,031, classified as averb, pronounced /dʌk/. dud is at rank #29,251, tagged as anoun, pronounced /dʌd/.

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 34282, this pair ranks #322,146 of 530,003 scored English confusable pairs - roughly mid-pack for confusability.

Orthographic DNA of duck vs dud

Shared letters: du. Private to "duck": ck. Private to "dud": -.

"duck" · 4 letters · shape CVCC  ·  "dud" · 3 letters · shape CVC

Known mistypes of this pair

  • duckdcuk · dduck · ducck · duckk · dukc · udck

Frequently Asked Questions

Can "duck" and "dud" be used interchangeably?
No - they are not even the same part of speech. "duck" is a verb and "dud" a noun, so a sentence built for one is usually ungrammatical with the other.
In ordinary English text, does "duck" or "dud" show up more?
"duck" is the more common of the two: it sits at frequency rank #5,031 in our English list, against #29,251 for "dud". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

Useful next steps

Eye-level mix-up between "duck" and "dud" is sorted above. Next: full entries or other pairs that share a letter shape.

  • Full dictionary entry for "duck" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "dud" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #322,146 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
  • "duck" and "dud" also get mixed up with nearby pairs, the highest-scored neighbour is "dox vs dud". 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 #322,146 of 530,003 scored English pairs, corpus vintage 2026-09-03, not spelling advice.

Source: Wiktionary (via kaikki.org) Structured Wiktionary extract

Source: FrequencyWords open word-frequency list