underlievsundermineWhat's the difference?

Which to use

“underlie” and “undermine” are a confusable English pair: similar on the page, but distinct in meaning, check the gloss before you choose.

#42,970
“underlie” frequency rank
#12,161
“undermine” frequency rank
55131
confusion score

Side-by-Side Comparison

Feature underlie undermine
Definition To lie in a position directly beneath something. To dig underneath (something), to make a passage for destructive or military purposes; to sap.

Where the eye mixes underlie and undermine

Muted = shared; highlighted = the visual trap. They share 7 letters in sequence. underlie runs 8 letters (VCCVCCVV) against undermine's 9 (VCCVCCVCV) - the length gap alone is often enough to separate them once you know to check it.

8 ch
underlie
9 ch
undermine

Look-alike desk: underlie vs undermine

A purely visual mix-up. underlie (/ˌʌn.dəˈlaɪ/) and undermine (/ˌʌn.dəˈmaɪn/) 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 55131, derived from the frequency rank of both members and their visual similarity.

underlie is recorded at frequency rank #42,970, classified as averb, pronounced /ˌʌn.dəˈlaɪ/. undermine is at rank #12,161, tagged as averb, pronounced /ˌʌn.dəˈmaɪn/.

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 55131, this pair ranks #135,974 of 530,003 scored English confusable pairs - roughly mid-pack for confusability.

Orthographic DNA of underlie vs undermine

Shared letters: deinru. Private to "underlie": l. Private to "undermine": m.

"underlie" · 8 letters · shape VCCVCCVV  ·  "undermine" · 9 letters · shape VCCVCCVCV

Known mistypes of this pair

  • underlie ← nuderlie · udnerlie · undderlie · undelrie · underile · underlei · underllie · underrlie
  • undermine ← nudermine · udnermine · unddermine · undemrine · underimne · undermien · underminne · undermmine

Frequently Asked Questions

Is swapping "underlie" for "undermine" ever safe?
No. They are said differently (/ˌʌn.dəˈlaɪ/ versus /ˌʌn.dəˈmaɪn/) and carry different meanings; reading the sentence aloud is usually enough to catch the wrong one.
Frequency check: "underlie" vs "undermine" - which ranks higher?
"undermine" is the more common of the two: it sits at frequency rank #12,161 in our English list, against #42,970 for "underlie". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

What to do next

Visual near-miss handled. Browse the word pages or a neighbour when the next look-alike shows up.

  • Full dictionary entry for "underlie" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "undermine" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #135,974 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
  • "underlie" and "undermine" 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 #135,974 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