CMV vs cos, What's the Difference?

Which to use

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

#46,987
“CMV” frequency rank: #6,553
“cos” frequency rank: 53540
confusion score

Side-by-Side Comparison

Feature	CMV	cos
Definition	Initialism of cytomegalovirus.	Synonym of romaine lettuce, a long-leaved variety of lettuce.

Letter map: CMV vs cos

Shared letters muted; letters that set CMV and cos apart highlighted. Shared run: 1.

3 ch

CMV

3 ch

cos

Pair insight - CMV / cos

CMV and cos are indexed as a confusable English pair. We have no recorded pronunciation or part of speech for both members, so the spelling overlap is what we can show you: they share most of their letters but differ in 2 positions. Our composite confusion score for this pair is 53540, derived from the frequency rank of both members and their visual similarity.

CMV is recorded at frequency rank #46,987, classified as anoun. cos is at rank #6,553, tagged as anoun, pronounced /kɑs/.

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 53540, this pair ranks #148,125 of 530,003 scored English confusable pairs - roughly mid-pack for confusability.

Orthographic DNA of CMV vs cos

Shared letters: c. Private to "CMV": mv. Private to "cos": os.

"CMV" · 3 letters · shape CCC · "cos" · 3 letters · shape CVC

Frequently Asked Questions

Is swapping "CMV" for "cos" ever safe?

No. They share most of their letters but differ in 2 positions, but the dictionary glosses above give them different meanings, so swapping one for the other changes what the sentence says.

Frequency check: "CMV" vs "cos" - which ranks higher?

"cos" is the more common of the two: it sits at frequency rank #6,553 in our English list, against #46,987 for "CMV". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

After this comparison

Pair "CMV" vs "cos" is on the table, pick a follow-up below.

Full dictionary entry for "CMV" with definition, IPA, and generated misspellings. Word entry
Full dictionary entry for "cos" - compare definitions side by side with the headword page. Word entry
This pair ranks #148,125 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
"CMV" and "cos" also get mixed up with nearby pairs, the highest-scored neighbour is "CGT vs CMV". Nearby pair

Confusion rank #148,125 of 530,003 scored English pairs, corpus vintage 2026-09-03, not spelling advice.