flaxvsfluTell them apart

Which to use

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

#27,151
“flax” frequency rank
#7,564
“flu” frequency rank
34715
confusion score

Side-by-Side Comparison

Feature flax flu
Definition A plant of the genus Linum, especially Linum usitatissimum, which has a single, slender stalk, about a foot and a half high, with blue flowers. Also known as linseed, especially when referring to the seeds. Influenza.

Where the eye mixes flax and flu

Muted = shared; highlighted = the visual trap. They share 2 letters in sequence.

4 ch
flax
3 ch
flu

Why the eye confuses flax with flu

A purely visual mix-up. flax (/flæks/) and flu (/fluː/) 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 34715, derived from the frequency rank of both members and their visual similarity.

flax is recorded at frequency rank #27,151, classified as anoun, pronounced /flæks/. flu is at rank #7,564, tagged as anoun, pronounced /fluː/.

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 34715, this pair ranks #318,353 of 530,003 scored English confusable pairs - roughly mid-pack for confusability.

Orthographic DNA of flax vs flu

Shared letters: fl. Private to "flax": ax. Private to "flu": u.

"flax" · 4 letters · shape CCVC  ·  "flu" · 3 letters · shape CCV

Known mistypes of this pair

  • flaxfalx · fflax · flaxx · fllax · flxa · lfax

Frequently Asked Questions

Is swapping "flax" for "flu" ever safe?
No. They are said differently (/flæks/ versus /fluː/) and carry different meanings; reading the sentence aloud is usually enough to catch the wrong one.
Which is more common, "flax" or "flu"?
"flu" is the more common of the two: it sits at frequency rank #7,564 in our English list, against #27,151 for "flax". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

What to do next

Eye-level mix-up between "flax" and "flu" is sorted above. Next: full entries or other pairs that share a letter shape.

  • Full dictionary entry for "flax" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "flu" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #318,353 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
  • "flax" and "flu" also get mixed up with nearby pairs, the highest-scored neighbour is "flail vs flax". 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 #318,353 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