arcovsarsonTell them apart

Quick tell: arco is a adverb, arson is a noun, so they fill different roles in a sentence.

Which to use

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

#49,190
“arco” frequency rank
#17,076
“arson” frequency rank
66266
confusion score

Side-by-Side Comparison

Feature arco arson
Definition A note in string instrument musical notation indicating that the bow is to be used in the usual way, usually following a passage that is played pizzicato. The crime of deliberately starting a fire with intent to cause damage.

Letter map: arco vs arson

Shared letters muted; letters that set arco and arson apart highlighted. Shared run: 3.

4 ch
arco
5 ch
arson

Grammar separator: arco vs arson

Our dataset has no pronunciation recorded for both members, so the reliable separator here is grammatical: arco is anadverb and arsonanoun. On the page they differ by 1 letter(s) in length. Our composite confusion score for this pair is 66266, derived from the frequency rank of both members and their visual similarity.

arco is recorded at frequency rank #49,190, classified as anadv. arson is at rank #17,076, tagged as anoun, pronounced /ˈɑɹsən/.

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 66266, this pair ranks #68,803 of 530,003 scored English confusable pairs - among the most confusable pairs.

Orthographic DNA of arco vs arson

Shared letters: aor. Private to "arco": c. Private to "arson": ns.

"arco" · 4 letters · shape VCCV  ·  "arson" · 5 letters · shape VCCVC

Known mistypes of this pair

  • arcoarcco · aroc · arrco · raco
  • arsonarosn · arrson · arsno · arsonn · arsson · asron · rason

Frequently Asked Questions

Do "arco" and "arson" mean the same thing in a sentence?
No - they are not even the same part of speech. "arco" is an adverb and "arson" a noun, so a sentence built for one is usually ungrammatical with the other.
Which is more common, "arco" or "arson"?
"arson" is the more common of the two: it sits at frequency rank #17,076 in our English list, against #49,190 for "arco". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

What to do next

Pair "arco" vs "arson" is on the table, pick a follow-up below.

  • Full dictionary entry for "arco" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "arson" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #68,803 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
  • "arco" and "arson" also get mixed up with nearby pairs, the highest-scored neighbour is "algo vs arco". 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 #68,803 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