Which to use
“Cosby” is a name and “costly” is an adjective - they look or sound alike but fill different roles in a sentence.
- #21,761
- “Cosby” frequency rank
- #7,899
- “costly” frequency rank
- 29660
- confusion score
Side-by-Side Comparison
| Feature | Cosby | costly |
|---|---|---|
| Definition | A village and civil parish in Blaby district, Leicestershire, England (OS grid ref SP5495). | Of high cost; expensive. |
Letter map: Cosby vs costly
Shared letters muted; letters that set Cosby and costly apart highlighted. Shared run: 4. Cosby runs 5 letters (CVCCV) against costly's 6 (CVCCCV) - the length gap alone is often enough to separate them once you know to check it.
Grammar separator: Cosby vs costly
Our dataset has no pronunciation recorded for both members, so the reliable separator here is grammatical: Cosby is aname and costlyanadjective. On the page they differ by 1 letter(s) in length. Our composite confusion score for this pair is 29660, derived from the frequency rank of both members and their visual similarity.
Cosby is recorded at frequency rank #21,761, classified as aname. costly is at rank #7,899, tagged as anadj, pronounced /ˈkɒst.li/.
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 29660, this pair ranks #361,115 of 530,003 scored English confusable pairs - roughly mid-pack for confusability.
Orthographic DNA of Cosby vs costly
Shared letters: cosy. Private to "Cosby": b. Private to "costly": lt.
"Cosby" · 5 letters · shape CVCCV · "costly" · 6 letters · shape CVCCCV
Known mistypes of this pair
Frequently Asked Questions
Is swapping "Cosby" for "costly" ever safe?
In ordinary English text, does "Cosby" or "costly" show up more?
Useful next steps
Done with this confusable. These links stay specific to "Cosby" and "costly".
- Full dictionary entry for "Cosby" with definition, IPA, and generated misspellings. Word entry
- Full dictionary entry for "costly" - compare definitions side by side with the headword page. Word entry
- This pair ranks #361,115 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
- "Cosby" and "costly" also get mixed up with nearby pairs, the highest-scored neighbour is "Cosby vs cubby". 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 #361,115 of 530,003 scored English pairs, corpus vintage 2026-09-03, not spelling advice.