acevsAUCWhich spelling fits?

Quick tell: ace is a noun, AUC is an adverb, so they fill different roles in a sentence.

Which to use

“ace” is a noun and “AUC” is an adverb - they look or sound alike but fill different roles in a sentence.

#5,930
“ace” frequency rank
#48,600
“AUC” frequency rank
54530
confusion score

Side-by-Side Comparison

Feature ace AUC
Definition A playing card showing a single pip, typically the highest or lowest ranking card in a game. According to the Roman era, which reckons the number of years passed from the foundation of the city of Rome by Romulus, now usually taken as 753 bc.

Letter map: ace vs AUC

Shared letters muted; letters that set ace and AUC apart highlighted. Shared run: 2.

3 ch
ace
3 ch
AUC

Role in the sentence - ace and AUC

Our dataset has no pronunciation recorded for both members, so the reliable separator here is grammatical: ace is anoun and AUCanadverb. On the page they share most of their letters but differ in 2 positions. Our composite confusion score for this pair is 54530, derived from the frequency rank of both members and their visual similarity.

ace is recorded at frequency rank #5,930, classified as anoun, pronounced /eɪs/. AUC is at rank #48,600, tagged as anadv.

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 54530, this pair ranks #140,354 of 530,003 scored English confusable pairs - roughly mid-pack for confusability.

Orthographic DNA of ace vs AUC

Shared letters: ac. Private to "ace": e. Private to "AUC": u.

"ace" · 3 letters · shape VCV  ·  "AUC" · 3 letters · shape VVC

Frequently Asked Questions

Can "ace" and "AUC" be used interchangeably?
No - they are not even the same part of speech. "ace" is a noun and "AUC" an adverb, so a sentence built for one is usually ungrammatical with the other.
Which is more common, "ace" or "AUC"?
"ace" is the more common of the two: it sits at frequency rank #5,930 in our English list, against #48,600 for "AUC". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

After this comparison

Pair "ace" vs "AUC" is on the table, pick a follow-up below.

  • Full dictionary entry for "ace" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "AUC" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #140,354 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
  • "ace" and "AUC" also get mixed up with nearby pairs, the highest-scored neighbour is "amb vs AUC". Nearby pair

Confusion rank #140,354 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