flexingvsflexionWhat's the difference?

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

Which to use

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

#26,425
“flexing” frequency rank
#47,628
“flexion” frequency rank
74053
confusion score

Side-by-Side Comparison

Feature flexing flexion
Definition present participle and gerund of flex The act of bending a joint, especially a bone joint; the counteraction of extension.

Where the eye mixes flexing and flexion

Muted = shared; highlighted = the visual trap. They share 6 letters in sequence.

7 ch
flexing
7 ch
flexion

Why the eye confuses flexing with flexion

These two trip readers on the page rather than in the ear: flexing is /ˈflɛksɪŋ/ while flexion is /ˈflɛk.ʃən/. Spoken aloud the problem disappears. In writing it persists, because they share most of their letters but differ in 2 positions, and the parts of speech differ too (verb vs noun), which is usually the fastest check. Our composite confusion score for this pair is 74053, derived from the frequency rank of both members and their visual similarity.

flexing is recorded at frequency rank #26,425, classified as averb, pronounced /ˈflɛksɪŋ/. flexion is at rank #47,628, tagged as anoun, pronounced /ˈflɛk.ʃən/.

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 74053, this pair ranks #37,534 of 530,003 scored English confusable pairs - among the most confusable pairs.

Orthographic DNA of flexing vs flexion

Shared letters: efilnx. Private to "flexing": g. Private to "flexion": o.

"flexing" · 7 letters · shape CCVCVCC  ·  "flexion" · 7 letters · shape CCVCVVC

Known mistypes of this pair

  • flexingfelxing · fflexing · fleixng · flexign · flexingg · flexinng · flexnig · flexxing
  • flexionfelxion · fflexion · fleixon · flexino · flexionn · flexoin · flexxion · fllexion

Frequently Asked Questions

Is swapping "flexing" for "flexion" ever safe?
No - they are not even the same part of speech. "flexing" is a verb and "flexion" a noun, so a sentence built for one is usually ungrammatical with the other.
Frequency check: "flexing" vs "flexion" - which ranks higher?
"flexing" is the more common of the two: it sits at frequency rank #26,425 in our English list, against #47,628 for "flexion". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

Useful next steps

Pronunciation already separates them, if the page still looks alike, the dictionary links below settle it.

  • Full dictionary entry for "flexing" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "flexion" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #37,534 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
  • "flexing" and "flexion" also get mixed up with nearby pairs, the highest-scored neighbour is "flaring vs flexing". 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 #37,534 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