psivspusWhich spelling fits?

Which to use

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

#16,099
“psi” frequency rank
#28,336
“pus” frequency rank
44435
confusion score

Side-by-Side Comparison

Feature psi pus
Definition The twenty-third letter of Classical and Modern Greek and the twenty-fifth letter of Old and Ancient Greek. A whitish-yellow or yellow substance composed primarily of dead white blood cells and dead pyogenic bacteria, normally found in regions of bacterial infection.

Where the eye mixes psi and pus

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

3 ch
psi
3 ch
pus

Visual trap between psi and pus

A purely visual mix-up. psi (/psaɪ/) and pus (/pʌs/) are said differently, so reading them aloud is the quickest way to catch the wrong one. On the page they stay close: they share most of their letters but differ in 2 positions. Our composite confusion score for this pair is 44435, derived from the frequency rank of both members and their visual similarity.

psi is recorded at frequency rank #16,099, classified as anoun, pronounced /psaɪ/. pus is at rank #28,336, tagged as anoun, pronounced /pʌs/.

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 44435, this pair ranks #230,604 of 530,003 scored English confusable pairs - roughly mid-pack for confusability.

Orthographic DNA of psi vs pus

Shared letters: ps. Private to "psi": i. Private to "pus": u.

"psi" · 3 letters · shape CCV  ·  "pus" · 3 letters · shape CVC

Frequently Asked Questions

Can "psi" and "pus" be used interchangeably?
No. They are said differently (/psaɪ/ versus /pʌs/) and carry different meanings; reading the sentence aloud is usually enough to catch the wrong one.
Frequency check: "psi" vs "pus" - which ranks higher?
"psi" is the more common of the two: it sits at frequency rank #16,099 in our English list, against #28,336 for "pus". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

Useful next steps

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

  • Full dictionary entry for "psi" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "pus" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #230,604 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
  • "psi" and "pus" also get mixed up with nearby pairs, the highest-scored neighbour is "PPA vs pus". Nearby pair

Confusion rank #230,604 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