cisvsCTWhich spelling fits?

Quick tell: cis is a adjective, CT is a noun, so they fill different roles in a sentence.

Which to use

“cis” is an adjective and “CT” is a noun - they look or sound alike but fill different roles in a sentence.

#13,115
“cis” frequency rank
#5,951
“CT” frequency rank
19066
confusion score

Side-by-Side Comparison

Feature cis CT
Definition Having two mutations on two genes on the same chromosome of a homologous pair. Initialism of computed tomography.

Letter map: cis vs CT

Shared letters muted; letters that set cis and CT apart highlighted. Shared run: 1.

3 ch
cis
2 ch
CT

Part-of-speech tell for cis / CT

Our dataset has no pronunciation recorded for both members, so the reliable separator here is grammatical: cis is anadjective and CTanoun. On the page they differ by 1 letter(s) in length. Our composite confusion score for this pair is 19066, derived from the frequency rank of both members and their visual similarity.

cis is recorded at frequency rank #13,115, classified as anadj, pronounced /sɪs/. CT is at rank #5,951, tagged as anoun.

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 19066, this pair ranks #440,732 of 530,003 scored English confusable pairs - a relatively easy-to-tell-apart pair.

Orthographic DNA of cis vs CT

Shared letters: c. Private to "cis": is. Private to "CT": t.

"cis" · 3 letters · shape CVC  ·  "CT" · 2 letters · shape CC

Frequently Asked Questions

Is swapping "cis" for "CT" ever safe?
No - they are not even the same part of speech. "cis" is an adjective and "CT" a noun, so a sentence built for one is usually ungrammatical with the other.
In ordinary English text, does "cis" or "CT" show up more?
"CT" is the more common of the two: it sits at frequency rank #5,951 in our English list, against #13,115 for "cis". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

Useful next steps

You've compared "cis" and "CT". Here's where to go from here.

  • Full dictionary entry for "cis" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "CT" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #440,732 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
  • "cis" and "CT" also get mixed up with nearby pairs, the highest-scored neighbour is "cis vs Crist". Nearby pair

Confusion rank #440,732 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