flackvsflakWhich spelling fits?

Quick tell: flack is a verb, flak is a noun, so they fill different roles in a sentence.

Which to use

“flack” is a verb and “flak” is a noun - they look or sound alike but fill different roles in a sentence.

#30,799
“flack” frequency rank
#26,792
“flak” frequency rank
57591
confusion score

Side-by-Side Comparison

Feature flack flak
Definition To flutter; palpitate. Ground-based anti-aircraft guns firing explosive shells.

Same sound, different letters: flack vs flak

Muted letters are shared; highlighted letters are the only spelling cue when pronunciation matches. Shared run: 4 letters.

5 ch
flack
4 ch
flak

Same sound, different spelling - flack / flak

Say them out loud and nothing separates them: flack and flak carry the same recorded pronunciation, /flæk/. Grammar is what tells them apart: one is averb, the other anoun, so most sentences will only accept one of them. They differ by 1 letter(s) in length. Our composite confusion score for this pair is 57591, derived from the frequency rank of both members and their visual similarity.

flack is recorded at frequency rank #30,799, classified as averb, pronounced /flæk/. flak is at rank #26,792, tagged as anoun, pronounced /flæk/.

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 57591, this pair ranks #118,312 of 530,003 scored English confusable pairs - among the most confusable pairs.

Orthographic DNA of flack vs flak

Shared letters: afkl. Private to "flack": c. Private to "flak": -.

"flack" · 5 letters · shape CCVCC  ·  "flak" · 4 letters · shape CCVC

Known mistypes of this pair

  • flackfalck · fflack · flacck · flackk · flakc · flcak · fllack · lfack
  • flakfflak · flakk · flka · fllak · lfak

Frequently Asked Questions

Do "flack" and "flak" mean the same thing in a sentence?
No - they are not even the same part of speech. "flack" is a verb and "flak" a noun, so a sentence built for one is usually ungrammatical with the other.
In ordinary English text, does "flack" or "flak" show up more?
"flak" is the more common of the two: it sits at frequency rank #26,792 in our English list, against #30,799 for "flack". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

What to do next

Sound matches; spelling doesn't. Use the exits below to lock the right form or check a cousin pair.

  • Full dictionary entry for "flack" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "flak" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #118,312 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
  • "flack" and "flak" also get mixed up with nearby pairs, the highest-scored neighbour is "flack vs flail". 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 #118,312 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