lunacyvsLundyTell them apart

Quick tell: lunacy is a noun, Lundy is a name, so they fill different roles in a sentence.

Which to use

“lunacy” is a noun and “Lundy” is a name - they look or sound alike but fill different roles in a sentence.

#32,485
“lunacy” frequency rank
#44,314
“Lundy” frequency rank
76799
confusion score

Side-by-Side Comparison

Feature lunacy Lundy
Definition The state of being mad, insanity An island in the Bristol Channel, off the coast of Devon, England, and included in Torridge district (OS grid ref SS14).

Letter map: lunacy vs Lundy

Shared letters muted; letters that set lunacy and Lundy apart highlighted. Shared run: 4. lunacy runs 6 letters (CVCVCV) against Lundy's 5 (CVCCV) - the length gap alone is often enough to separate them once you know to check it.

6 ch
lunacy
5 ch
Lundy

Role in the sentence - lunacy and Lundy

Our dataset has no pronunciation recorded for both members, so the reliable separator here is grammatical: lunacy is anoun and Lundyaname. On the page they differ by 1 letter(s) in length. Our composite confusion score for this pair is 76799, derived from the frequency rank of both members and their visual similarity.

lunacy is recorded at frequency rank #32,485, classified as anoun, pronounced /ˈluː.nə.si/. Lundy is at rank #44,314, tagged as aname.

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 76799, this pair ranks #29,098 of 530,003 scored English confusable pairs - among the most confusable pairs.

Orthographic DNA of lunacy vs Lundy

Shared letters: lnuy. Private to "lunacy": ac. Private to "Lundy": d.

"lunacy" · 6 letters · shape CVCVCV  ·  "Lundy" · 5 letters · shape CVCCV

Known mistypes of this pair

  • lunacy ← llunacy · lnuacy · luancy · lunaccy · lunacyy · lunayc · luncay · lunnacy
  • Lundy ← llundy · lnudy · ludny · lunddy · lundyy · lunndy · lunyd · ulndy

Frequently Asked Questions

Is swapping "lunacy" for "Lundy" ever safe?
No - they are not even the same part of speech. "lunacy" is a noun and "Lundy" a name, so a sentence built for one is usually ungrammatical with the other.
In ordinary English text, does "lunacy" or "Lundy" show up more?
"lunacy" is the more common of the two: it sits at frequency rank #32,485 in our English list, against #44,314 for "Lundy". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

Useful next steps

You've compared "lunacy" and "Lundy". Here's where to go from here.

  • Full dictionary entry for "lunacy" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "Lundy" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #29,098 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
  • "lunacy" and "Lundy" also get mixed up with nearby pairs, the highest-scored neighbour is "Laney vs Lundy". 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 #29,098 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