fifthvsfilthyTell them apart

Which to use

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

#1,719
“fifth” frequency rank
#9,608
“filthy” frequency rank
11327
confusion score

Side-by-Side Comparison

Feature fifth filthy
Definition The ordinal form of the number five. Covered with filth; very dirty.

Where the eye mixes fifth and filthy

Muted = shared; highlighted = the visual trap. They share 4 letters in sequence.

5 ch
fifth
6 ch
filthy

Look-alike desk: fifth vs filthy

A purely visual mix-up. fifth (/fɪfθ/) and filthy (/ˈfɪlθi/) 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 11327, derived from the frequency rank of both members and their visual similarity.

fifth is recorded at frequency rank #1,719, classified as anadj, pronounced /fɪfθ/. filthy is at rank #9,608, tagged as anadj, pronounced /ˈfɪlθi/.

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 11327, this pair ranks #487,662 of 530,003 scored English confusable pairs - a relatively easy-to-tell-apart pair.

Orthographic DNA of fifth vs filthy

Shared letters: fhit. Private to "fifth": -. Private to "filthy": ly.

"fifth" · 5 letters · shape CVCCC  ·  "filthy" · 6 letters · shape CVCCCV

Known mistypes of this pair

  • fifthffifth · ffith · fiffth · fifht · fifthh · fiftth · fitfh · iffth
  • filthyffilthy · filhty · fillthy · filthhy · filthyy · filtthy · filtyh · fitlhy

Frequently Asked Questions

Is swapping "fifth" for "filthy" ever safe?
No. They are said differently (/fɪfθ/ versus /ˈfɪlθi/) and carry different meanings; reading the sentence aloud is usually enough to catch the wrong one.
Frequency check: "fifth" vs "filthy" - which ranks higher?
"fifth" is the more common of the two: it sits at frequency rank #1,719 in our English list, against #9,608 for "filthy". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

After this comparison

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

  • Full dictionary entry for "fifth" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "filthy" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #487,662 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
  • "fifth" and "filthy" also get mixed up with nearby pairs, the highest-scored neighbour is "filthy vs frothy". 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 #487,662 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