Which to use
“louse” is a noun and “lousy” is an adjective - they look or sound alike but fill different roles in a sentence.
- #47,167
- “louse” frequency rank
- #19,383
- “lousy” frequency rank
- 66550
- confusion score
Side-by-Side Comparison
| Feature | louse | lousy |
|---|---|---|
| Definition | A small parasitic wingless insect of the order Psocodea. | Remarkably bad; of poor quality. |
Where the eye mixes louse and lousy
Muted = shared; highlighted = the visual trap. They share 4 letters in sequence. louse and lousy follow the identical consonant-vowel pattern (CVVCV). Same shape at a glance is often the real trap, independent of shared letters.
Look-alike desk: louse vs lousy
These two trip readers on the page rather than in the ear: louse is /laʊs/ while lousy is /ˈlaʊ.zi/. Spoken aloud the problem disappears. In writing it persists, because they differ by a single letter - e in “louse” becomes y in “lousy”, and the parts of speech differ too (noun vs adjective), which is usually the fastest check. Our composite confusion score for this pair is 66550, derived from the frequency rank of both members and their visual similarity.
louse is recorded at frequency rank #47,167, classified as anoun, pronounced /laʊs/. lousy is at rank #19,383, tagged as anadj, pronounced /ˈlaʊ.zi/.
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 66550, this pair ranks #67,449 of 530,003 scored English confusable pairs - among the most confusable pairs.
Orthographic DNA of louse vs lousy
Shared letters: losu. Private to "louse": e. Private to "lousy": y.
"louse" · 5 letters · shape CVVCV · "lousy" · 5 letters · shape CVVCV
Known mistypes of this pair
Frequently Asked Questions
Can "louse" and "lousy" be used interchangeably?
Which is more common, "louse" or "lousy"?
What to do next
Eye-level mix-up between "louse" and "lousy" is sorted above. Next: full entries or other pairs that share a letter shape.
- Full dictionary entry for "louse" with definition, IPA, and generated misspellings. Word entry
- Full dictionary entry for "lousy" - compare definitions side by side with the headword page. Word entry
- This pair ranks #67,449 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
- "louse" and "lousy" also get mixed up with nearby pairs, the highest-scored neighbour is "lope vs louse". 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 #67,449 of 530,003 scored English pairs, corpus vintage 2026-09-03, not spelling advice.