sulfur

/ˈsʌl.fə/

//ˈsʌl.fə// noun

By · According to Wiktionary data (CC BY-SA) ·

"sulfur" is a 6-letter English headword indexed on PlainSpell.

The verdict

“sulfur” has 9 generated spelling variants in the English index at frequency #16,594. The variants make it a useful spelling check.

#16,594
frequency rank, English
6,566
“S” headwords
9
tracked misspellings
7
confusable pairs

According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - A chemical element with atomic number 16, having a bright yellow color and characteristic smell, used commercially in a variety of products such as insecticides, black powder, and matchsticks.

Corpus desk

Index EN-sulfur · sulfur · English

sulfur · rank #16,594 · 9 variants · 7 confusables

  • FREQ-MID #16,594
  • LEN-LONG 6 letters
  • VOW-2 2 vowels
  • CONFUS-MID 7 pairs
  • VAR-MID 9 variants
  • BOOK-DENSE 6,566
  • PHOTO-FINISH stringent

Nearest frequency peer: stringent (-1 rank slots)

Read with this headword: Spelling guide for this pattern

Desk codes from Wiktionary headword shape, FrequencyWords rank tier, confusable-pair count, generated misspelling depth, letter-cohort book size, and photo-finish peer. Not a difficulty grade.

Rank peers near misspelling magnet “sulfur”

Same rarity band: useful when a typo lands on a peer headword

corpus weight

What this shows “sulfur” sits among these FrequencyWords peers; misspelling depth is tracked separately in the edit-distance chart.

Source FrequencyWords open word-frequency list As of September 3, 2026

Visual similarity to commonly confused words

How many letter changes separate each confused pair (Levenshtein distance, normalized).

sulfur vs Sulu
50% similar
sulfur vs surfer
67% similar
sulfur vs Sulphur
57% similar

Source: PlainSpell confusable corpus (Wiktionary, CC BY-SA).

Key facts for sulfur
PropertyValue
Headwordsulfur
LanguageEnglish
Part of speechNoun
IPA/ˈsʌl.fə/
Letters6
Frequency rank#16,594
Misspellings tracked9
Confusable pairs7
SourceWiktionary (kaikki.org)

Frequency seat of misspelling magnet “sulfur”

Word frequency stretches from the small set of words we reach for constantly (left) out to the long tail barely used once in a while (right).sulfurlands here:

#1#100#1K#10K#100K
← used constantlyrarely used →

Ticks step logarithmically, so each one marks a roughly tenfold drop in how often the word turns up. Same rarity band neighbours include “stringent” (#16,593), “stride” (#16,592), “surfaced” (#16,596). Among 6,566 “S” headwords, “sulfur” is #16,594. Source: FrequencyWords open word-frequency list.

A misspelling magnet

The generator records 9 spelling variants around sulfur (IPA /ˈsʌl.fə/), anoun. Corpus frequency is #16,594 among 6,566 “S” headwords. Wiktionary lists 4 senses, so context still picks the gloss.

Our generated misspelling index lists 9 likely wrong-spelling variants for sulfur, with forms such as "slufur", "ssulfur", and "suflur". Every one of these variants traces to a single-character edit -- an added or dropped letter, a swapped consonant, or a vowel swap -- the kind of slip a spell-checker is built to catch. It also participates in 7 confusable-pair relationships, "Sulu", "surfer", "Sulphur", and more, since the words sound or look close enough that writers reach for the wrong one mid-sentence.

Etymologically, the entry records: From Middle English sulphur, borrowed from Anglo-Norman sulfre, from Latin sulfur, from sulpur itself of uncertain origin. Displaced Old English swefl and largely displaced brimstone. The correct English form is sulfur, spelled S-U-L-F-U-R.

Definition

  1. 1
    A chemical element with atomic number 16, having a bright yellow color and characteristic smell, used commercially in a variety of products such as insecticides, black powder, and matchsticks.
  2. 2
    A chemical element with atomic number 16, having a bright yellow color and characteristic smell, used commercially in a variety of products such as insecticides, black powder, and matchsticks.
  3. 3
    A yellowish green colour, like that of sulfur.
  4. 4
    Any of various pierid butterflies of the subfamily Coliadinae, especially the sulfur-coloured species.

Recorded use

Wiktionary examples

These source excerpts show how sulfur appears in context. They illustrate usage; the definition above remains the entry’s reference meaning.

  1. A Dungeon horrible, on all ſides round / As one great Furnace flam’d, yet from thoſe flames / No light, but rather darkneſs viſible / […] but torture without end / Still urges, and a fiery Deluge, fed / With ever-burning Sulphur unconſum’d:
  2. Sure only that man is mortal; that with the life of one mortal snaps irrevocably the wonderfulest talisman, and all Dubarrydom rushes off, with tumult, into infinite Space; and ye, as subterranean Apparitions are wont, vanish utterly,—leaving only a smell of sulphur!

Etymology

From Middle English sulphur, borrowed from Anglo-Norman sulfre, from Latin sulfur, from sulpur itself of uncertain origin. Displaced Old English swefl and largely displaced brimstone.

This word in other languages

azufre(Español)soufre(Français)Schwefel(Deutsch)enxofre(Português)

Common misspellings

Also misspelled as:

  • slufur
  • ssulfur
  • suflur
  • sulffur
  • sulfru
  • sulfurr
  • sullfur
  • sulufr
  • uslfur

Misspelling Pattern Breakdown

How far each generated variant is from the correct spelling of sulfur - measured in single-character edits (insert, delete, or substitute a letter). Larger bars are easier to catch; one-edit slips are the sneakiest.

slufur2ssulfur1suflur2sulffur1sulfru2sulfurr1sullfur1sulufr2
Edit distance from "sulfur"

Definitions, pronunciation, and etymology for this entry are drawn from Wiktionary via the kaikki.org structured extract (CC BY-SA); frequency ordering uses the FrequencyWords open word-frequency list (2018 English corpus, MIT). See the methodology for how each field is sourced and updated.

Frequently Asked Questions

How do you spell "sulfur"?
"sulfur" is spelled S-U-L-F-U-R. The IPA pronunciation is /ˈsʌl.fə/.
What does "sulfur" mean?
As a noun, "sulfur" means: A chemical element with atomic number 16, having a bright yellow color and characteristic smell, used commercially in a variety of products such as insecticides, black powder, and matchsticks.
What words are commonly confused with "sulfur"?
"sulfur" is commonly confused with "Sulu", "surfer", "Sulphur". These words look or sound similar but have different meanings. PlainSpell provides detailed comparisons for each pair.
How do you pronounce "sulfur"?
The IPA (International Phonetic Alphabet) transcription for "sulfur" is /ˈsʌl.fə/. Click the speaker icon on the pronunciation badge above to hear it spoken aloud where audio is available.
What is the origin of the word "sulfur"?
From Middle English sulphur, borrowed from Anglo-Norman sulfre, from Latin sulfur, from sulpur itself of uncertain origin. Displaced Old English swefl and largely displaced brimstone. See the full etymology section above for more details.
Is PlainSpell free to use?
Yes, PlainSpell is a completely free word reference. You can look up definitions, pronunciations, confusable pairs, homophones, and spelling corrections across 5 languages without any sign-up or subscription.

Similar English words by spelling shape

Same letter count and similar misspelling depth for "sulfur", not the corpus desk frequency band.

Same letter count

Frequency-ranked English headwords with 6 letters (nearest by frequency rank).

stride#16,592Suzuki#16,597slated#16,587trough#16,606

Similar misspelling depth

Headwords with a similar count of attested misspellings (9 here; floor ≥5).

torrent9 variantstrainee9 variantstripped9 variantsunjust9 variants

Source: Wiktionary (via kaikki.org) Structured Wiktionary extract

Source: FrequencyWords open word-frequency list