FLvsfoulWhat's the difference?

Quick tell: FL is a noun, foul is an adjective, so they fill different roles in a sentence.

Which to use

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

#6,140
“FL” frequency rank
#6,574
“foul” frequency rank
12714
confusion score

Side-by-Side Comparison

Feature FL foul
Definition Abbreviation of foreign language. Covered with, or containing unclean matter; dirty.

Letter map: FL vs foul

Shared letters muted; letters that set FL and foul apart highlighted. Shared run: 2.

2 ch
FL
4 ch
foul

Part-of-speech tell for FL / foul

Our dataset has no pronunciation recorded for both members, so the reliable separator here is grammatical: FL is anoun and foulanadjective. On the page they differ by 2 letter(s) in length. Our composite confusion score for this pair is 12714, derived from the frequency rank of both members and their visual similarity.

FL is recorded at frequency rank #6,140, classified as anoun. foul is at rank #6,574, tagged as anadj, pronounced /faʊl/.

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 12714, this pair ranks #479,953 of 530,003 scored English confusable pairs - a relatively easy-to-tell-apart pair.

Orthographic DNA of FL vs foul

Shared letters: fl. Private to "FL": -. Private to "foul": ou.

"FL" · 2 letters · shape CC  ·  "foul" · 4 letters · shape CVVC

Known mistypes of this pair

  • foulffoul · folu · foull · fuol · oful

Frequently Asked Questions

Can "FL" and "foul" be used interchangeably?
No - they are not even the same part of speech. "FL" is a noun and "foul" an adjective, so a sentence built for one is usually ungrammatical with the other.
Frequency check: "FL" vs "foul" - which ranks higher?
"FL" is the more common of the two: it sits at frequency rank #6,140 in our English list, against #6,574 for "foul". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

What to do next

Pair "FL" vs "foul" is on the table, pick a follow-up below.

  • Full dictionary entry for "FL" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "foul" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #479,953 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
  • "FL" and "foul" also get mixed up with nearby pairs, the highest-scored neighbour is "FOMO vs foul". 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 #479,953 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