spleenvssullenWhich spelling fits?

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

Which to use

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

#24,321
“spleen” frequency rank
#41,399
“sullen” frequency rank
65720
confusion score

Side-by-Side Comparison

Feature spleen sullen
Definition In vertebrates, including humans, a ductless vascular gland, located in the left upper abdomen near the stomach, which destroys old red blood cells, removes debris from the bloodstream, acts as a reservoir of blood, and produces lymphocytes. Having a brooding ill temper; sulky.

Where the eye mixes spleen and sullen

Muted = shared; highlighted = the visual trap. They share 4 letters in sequence. spleen (CCCVVC) and sullen (CVCCVC) run the same length but a different consonant-vowel pattern - the shape difference is usually the fastest tell.

6 ch
spleen
6 ch
sullen

Look-alike desk: spleen vs sullen

These two trip readers on the page rather than in the ear: spleen is /spliːn/ while sullen is /ˈsʌlən/. 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 (noun vs adjective), which is usually the fastest check. Our composite confusion score for this pair is 65720, derived from the frequency rank of both members and their visual similarity.

spleen is recorded at frequency rank #24,321, classified as anoun, pronounced /spliːn/. sullen is at rank #41,399, tagged as anadj, pronounced /ˈsʌlən/.

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 65720, this pair ranks #71,403 of 530,003 scored English confusable pairs - among the most confusable pairs.

Orthographic DNA of spleen vs sullen

Shared letters: elns. Private to "spleen": p. Private to "sullen": u.

"spleen" · 6 letters · shape CCCVVC  ·  "sullen" · 6 letters · shape CVCCVC

Known mistypes of this pair

  • spleen ← psleen · slpeen · spelen · spleenn · splen · splene · splleen · sppleen
  • sullen ← slulen · ssullen · suleln · sulen · sullenn · sullne · usllen

Frequently Asked Questions

Can "spleen" and "sullen" be used interchangeably?
No - they are not even the same part of speech. "spleen" is a noun and "sullen" an adjective, so a sentence built for one is usually ungrammatical with the other.
Which is more common, "spleen" or "sullen"?
"spleen" is the more common of the two: it sits at frequency rank #24,321 in our English list, against #41,399 for "sullen". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

After this comparison

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

  • Full dictionary entry for "spleen" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "sullen" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #71,403 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
  • "spleen" and "sullen" also get mixed up with nearby pairs, the highest-scored neighbour is "silken vs sullen". 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 #71,403 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