Which to use
“undermine” and “underpin” are a confusable English pair: similar on the page, but distinct in meaning, check the gloss before you choose.
- #12,161
- “undermine” frequency rank
- #43,448
- “underpin” frequency rank
- 55609
- confusion score
Side-by-Side Comparison
| Feature | undermine | underpin |
|---|---|---|
| Definition | To dig underneath (something), to make a passage for destructive or military purposes; to sap. | To support from below with props or masonry. |
Where the eye mixes undermine and underpin
Muted = shared; highlighted = the visual trap. They share 7 letters in sequence. undermine runs 9 letters (VCCVCCVCV) against underpin's 8 (VCCVCCVC) - the length gap alone is often enough to separate them once you know to check it.
Why the eye confuses undermine with underpin
A purely visual mix-up. undermine (/ˌʌn.dəˈmaɪn/) and underpin (/ˌʌn.dəˈpɪn/) are said differently, so reading them aloud is the quickest way to catch the wrong one. On the page they stay close: they differ by 1 letter(s) in length. Our composite confusion score for this pair is 55609, derived from the frequency rank of both members and their visual similarity.
undermine is recorded at frequency rank #12,161, classified as averb, pronounced /ˌʌn.dəˈmaɪn/. underpin is at rank #43,448, tagged as averb, pronounced /ˌʌn.dəˈpɪn/.
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 55609, this pair ranks #132,299 of 530,003 scored English confusable pairs - among the most confusable pairs.
Orthographic DNA of undermine vs underpin
Shared letters: deinru. Private to "undermine": m. Private to "underpin": p.
"undermine" · 9 letters · shape VCCVCCVCV · "underpin" · 8 letters · shape VCCVCCVC
Known mistypes of this pair
Frequently Asked Questions
Do "undermine" and "underpin" mean the same thing in a sentence?
Frequency check: "undermine" vs "underpin" - which ranks higher?
What to do next
Eye-level mix-up between "undermine" and "underpin" is sorted above. Next: full entries or other pairs that share a letter shape.
- Full dictionary entry for "undermine" with definition, IPA, and generated misspellings. Word entry
- Full dictionary entry for "underpin" - compare definitions side by side with the headword page. Word entry
- This pair ranks #132,299 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
- "undermine" and "underpin" also get mixed up with nearby pairs, the highest-scored neighbour is "underlie vs underpin". 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 #132,299 of 530,003 scored English pairs, corpus vintage 2026-09-03, not spelling advice.