sludgevssmudgedTell them apart

Quick tell: sludge is a noun, smudged is an adjective, so they fill different roles in a sentence.

Which to use

“sludge” is a noun and “smudged” is an adjective - they look or sound alike but fill different roles in a sentence.

#21,661
“sludge” frequency rank
#49,053
“smudged” frequency rank
70714
confusion score

Side-by-Side Comparison

Feature sludge smudged
Definition Solids separated from suspension in a liquid. Blurred as by being rubbed.

Letter map: sludge vs smudged

Shared letters muted; letters that set sludge and smudged apart highlighted. Shared run: 5. sludge runs 6 letters (CCVCCV) against smudged's 7 (CCVCCVC) - the length gap alone is often enough to separate them once you know to check it.

6 ch
sludge
7 ch
smudged

Role in the sentence - sludge and smudged

Our dataset has no pronunciation recorded for both members, so the reliable separator here is grammatical: sludge is anoun and smudgedanadjective. On the page they differ by 1 letter(s) in length. Our composite confusion score for this pair is 70714, derived from the frequency rank of both members and their visual similarity.

sludge is recorded at frequency rank #21,661, classified as anoun, pronounced /slʌd͡ʒ/. smudged is at rank #49,053, tagged as anadj.

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 70714, this pair ranks #49,425 of 530,003 scored English confusable pairs - among the most confusable pairs.

Orthographic DNA of sludge vs smudged

Shared letters: degsu. Private to "sludge": l. Private to "smudged": m.

"sludge" · 6 letters · shape CCVCCV  ·  "smudged" · 7 letters · shape CCVCCVC

Known mistypes of this pair

  • sludgelsudge · slduge · slludge · sluddge · sludeg · sludgge · slugde · ssludge
  • smudgedmsudged · smduged · smmudged · smuddged · smudegd · smudgde · smudgedd · smudgged

Frequently Asked Questions

Is swapping "sludge" for "smudged" ever safe?
No - they are not even the same part of speech. "sludge" is a noun and "smudged" an adjective, so a sentence built for one is usually ungrammatical with the other.
In ordinary English text, does "sludge" or "smudged" show up more?
"sludge" is the more common of the two: it sits at frequency rank #21,661 in our English list, against #49,053 for "smudged". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

Useful next steps

Pair "sludge" vs "smudged" is on the table, pick a follow-up below.

  • Full dictionary entry for "sludge" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "smudged" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #49,425 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
  • "sludge" and "smudged" also get mixed up with nearby pairs, the highest-scored neighbour is "smudge vs smudged". 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 #49,425 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