Which to use
“sill” is a noun and “sully” is a verb - they look or sound alike but fill different roles in a sentence.
- #29,086
- “sill” frequency rank
- #25,227
- “sully” frequency rank
- 54313
- confusion score
Side-by-Side Comparison
| Feature | sill | sully |
|---|---|---|
| Definition | A breast wall; window breast; horizontal brink which forms the base of a window. | To soil or stain; to dirty. |
Where the eye mixes sill and sully
Muted = shared; highlighted = the visual trap. They share 3 letters in sequence. sill runs 4 letters (CVCC) against sully's 5 (CVCCV) - the length gap alone is often enough to separate them once you know to check it.
Look-alike desk: sill vs sully
These two trip readers on the page rather than in the ear: sill is /sɪl/ while sully is /ˈsʌli/. 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 (noun vs verb), which is usually the fastest check. Our composite confusion score for this pair is 54313, derived from the frequency rank of both members and their visual similarity.
sill is recorded at frequency rank #29,086, classified as anoun, pronounced /sɪl/. sully is at rank #25,227, tagged as averb, pronounced /ˈsʌli/.
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 54313, this pair ranks #142,028 of 530,003 scored English confusable pairs - roughly mid-pack for confusability.
Orthographic DNA of sill vs sully
Shared letters: ls. Private to "sill": i. Private to "sully": uy.
"sill" · 4 letters · shape CVCC · "sully" · 5 letters · shape CVCCV
Known mistypes of this pair
Frequently Asked Questions
Do "sill" and "sully" mean the same thing in a sentence?
In ordinary English text, does "sill" or "sully" show up more?
Useful next steps
Eye-level mix-up between "sill" and "sully" is sorted above. Next: full entries or other pairs that share a letter shape.
- Full dictionary entry for "sill" with definition, IPA, and generated misspellings. Word entry
- Full dictionary entry for "sully" - compare definitions side by side with the headword page. Word entry
- This pair ranks #142,028 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
- "sill" and "sully" also get mixed up with nearby pairs, the highest-scored neighbour is "Sif vs sill". 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 #142,028 of 530,003 scored English pairs, corpus vintage 2026-09-03, not spelling advice.