Which to use
“infection” is a noun and “infectious” is an adjective - they look or sound alike but fill different roles in a sentence.
- #4,093
- “infection” frequency rank
- #9,481
- “infectious” frequency rank
- 13574
- confusion score
Side-by-Side Comparison
| Feature | infection | infectious |
|---|---|---|
| Definition | The act or process of infecting. | Caused by an agent that enters the host's body (such as a bacterium, virus, parasite, or prion); often, also, transmitted among hosts via any of various routes (for example, contact, droplet-borne, airborne, waterborne, foodborne, fomite-borne, or bloodborne). |
Where the spellings diverge
Shared letters are muted; the letters that actually set infection and infectious apart are highlighted. They share 8 letters in sequence, which is exactly why the eye skips the difference.
Spelling & Dictionary Insight
These two trip readers on the page rather than in the ear: infection is /ɪnˈfɛkʃən/ while infectious is /ɪnˈfɛk.ʃəs/. Spoken aloud the problem disappears. In writing it persists, because they differ by 1 letter(s) in length, and the parts of speech differ too (noun vs adjective), which is usually the fastest check. Our composite confusion score for this pair is 13574, derived from the frequency rank of both members and their visual similarity.
infection is recorded at frequency rank #4,093, classified as anoun, pronounced /ɪnˈfɛkʃən/. infectious is at rank #9,481, tagged as anadj, pronounced /ɪnˈfɛk.ʃəs/.
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 13574, this pair ranks #474,997 of 530,003 scored English confusable pairs - a relatively easy-to-tell-apart pair.
Orthographic DNA of infection vs infectious
Shared letters: cefinot. Private to "infection": -. Private to "infectious": su.
"infection" · 9 letters · shape VCCVCCVVC · "infectious" · 10 letters · shape VCCVCCVVVC
Known mistypes of this pair
- infection ← ifnection · inefction · infcetion · infecction · infeciton · infecsion · infectino · infectionn
- infectious ← ifnectious · inefctious · infcetious · infecctious · infecitous · infectiosu · infectiouss · infectiuos
Frequency comparison
Frequently Asked Questions
Can "infection" and "infectious" be used interchangeably?
Which is more common, "infection" or "infectious"?
Remembering infection vs infectious
The fastest way to pick the right one every time.
- Check the role first: if you need a noun, it's “infection”; for an adjective, it's “infectious”.
- See each word in full, definition, IPA, etymology and its other confusables. Full “infection” entry
- Browse more pairs most likely to be confused. Most confusable