Which to use
“castor” and “custom” are a confusable English pair: similar on the page, but distinct in meaning, check the gloss before you choose.
- #22,921
- “castor” frequency rank
- #3,421
- “custom” frequency rank
- 26342
- confusion score
Side-by-Side Comparison
| Feature | castor | custom |
|---|---|---|
| Definition | A hat made from the fur of the beaver. | Frequent repetition of the same behavior; way of behavior common to many; ordinary manner; habitual practice; method of doing, living or behaving. |
Where the eye mixes castor and custom
Muted = shared; highlighted = the visual trap. They share 4 letters in sequence.
Look-alike desk: castor vs custom
A purely visual mix-up. castor (/ˈkɑːs.tə/) and custom (/ˈkʌstəm/) are said differently, so reading them aloud is the quickest way to catch the wrong one. On the page they stay close: they share most of their letters but differ in 2 positions. Our composite confusion score for this pair is 26342, derived from the frequency rank of both members and their visual similarity.
castor is recorded at frequency rank #22,921, classified as anoun, pronounced /ˈkɑːs.tə/. custom is at rank #3,421, tagged as anoun, pronounced /ˈkʌstəm/.
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 26342, this pair ranks #387,396 of 530,003 scored English confusable pairs - roughly mid-pack for confusability.
Orthographic DNA of castor vs custom
Shared letters: cost. Private to "castor": ar. Private to "custom": mu.
"castor" · 6 letters · shape CVCCVC · "custom" · 6 letters · shape CVCCVC
Known mistypes of this pair
Frequently Asked Questions
Do "castor" and "custom" mean the same thing in a sentence?
Which is more common, "castor" or "custom"?
What to do next
Pronunciation already separates them, if the page still looks alike, the dictionary links below settle it.
- Full dictionary entry for "castor" with definition, IPA, and generated misspellings. Word entry
- Full dictionary entry for "custom" - compare definitions side by side with the headword page. Word entry
- This pair ranks #387,396 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
- "castor" and "custom" also get mixed up with nearby pairs, the highest-scored neighbour is "captor vs castor". 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 #387,396 of 530,003 scored English pairs, corpus vintage 2026-09-03, not spelling advice.