alum

/ˈæl.əm/

//ˈæl.əm// noun

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

"alum" is a 4-letter English headword indexed on PlainSpell.

The verdict

“alum” has 5 generated spelling variants in the English index at frequency #20,832. The variants make it a useful spelling check.

#20,832
frequency rank, English
3,931
“A” headwords
5
tracked misspellings
20
confusable pairs

According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - An astringent salt, usually occurring in the form of pale crystals, much used in the dyeing and tanning trade and in certain medicines, and now understood to be a double sulphate of potassium and a...

Corpus desk

Index EN-alum · alum · English

alum · rank #20,832 · 5 variants · 20 confusables

  • FREQ-MID #20,832
  • LEN-MID 4 letters
  • VOW-2 2 vowels
  • CONFUS-HIGH 20 pairs
  • VAR-MID 5 variants
  • BOOK-MID 3,931
  • PHOTO-FINISH alkaline

Nearest frequency peer: alkaline (-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 “alum”

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

corpus weight

What this shows “alum” 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).

alum vs AM
0% similar
alum vs AU
0% similar
alum vs arm
50% similar

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

Key facts for alum
PropertyValue
Headwordalum
LanguageEnglish
Part of speechNoun
IPA/ˈæl.əm/
Letters4
Frequency rank#20,832
Misspellings tracked5
Confusable pairs20
SourceWiktionary (kaikki.org)

Frequency seat of misspelling magnet “alum”

Every-word frequency runs from the handful of words we use constantly (left) to the long tail used once in a blue moon (right).alumlands here:

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

The axis is logarithmic, with each marked tick roughly ten times rarer than the last. Same rarity band neighbours include “alkaline” (#20,831), “André” (#20,833), “Alistair” (#20,830). Among 3,931 “A” headwords, “alum” is #20,832. Source: FrequencyWords open word-frequency list.

A misspelling magnet

The generator records 5 spelling variants around alum (IPA /ˈæl.əm/), anoun. Corpus frequency is #20,832 among 3,931 “A” headwords. Wiktionary lists 2 senses, so context still picks the gloss.

Our generated misspelling index lists 5 likely wrong-spelling variants for alum, with forms such as "allum", "almu", and "alumm". Each of these forms differs from the correct spelling by one small edit: a doubled letter, a dropped silent letter, or a substituted vowel. It also participates in 20 confusable-pair relationships, "AM", "AU", "arm", 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 alum, alum, alym, alyme, from Anglo-Norman alum, alun, from Latin alūmen. The correct English form is alum, spelled A-L-U-M.

Definition

  1. 1
    An astringent salt, usually occurring in the form of pale crystals, much used in the dyeing and tanning trade and in certain medicines, and now understood to be a double sulphate of potassium and aluminium (K₂SO₄·Al₂(SO₄)₃·24H₂O).
  2. 2
    Any similar double sulphate in which either or both of the potassium and aluminium is wholly or partly replaced by other univalent or tervalent cations.

Recorded use

Wiktionary examples

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

  1. Venice also needed alum for trade, since it was the point of departure for overland transportation of alum to southern Germany and its cloth-manufacturing Free Cities.
  2. A natural astringent and antiseptic, potassium alum was coveted for its medicinal and cosmetic properties.

Etymology

From Middle English alum, alum, alym, alyme, from Anglo-Norman alum, alun, from Latin alūmen.

Synonyms

potash alum

This word in other languages

alumbre(Español)alun(Français)Alaun(Deutsch)

Common misspellings

Also misspelled as:

  • allum
  • almu
  • alumm
  • aulm
  • laum

Misspelling Pattern Breakdown

How far each generated variant is from the correct spelling of alum - expressed in single-character edits (insert, delete, or swap one letter). Bigger bars stand out at a glance; a one-edit slip is the hardest to catch.

allum1almu2alumm1aulm2laum2
Edit distance from "alum"

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 "alum"?
"alum" is spelled A-L-U-M. The IPA pronunciation is /ˈæl.əm/.
What does "alum" mean?
As a noun, "alum" means: An astringent salt, usually occurring in the form of pale crystals, much used in the dyeing and tanning trade and in certain medicines, and now understood to be a double sulphate of potassium and a...
What words are commonly confused with "alum"?
"alum" is commonly confused with "AM", "AU", "arm". These words look or sound similar but have different meanings. PlainSpell provides detailed comparisons for each pair.
How do you pronounce "alum"?
The IPA (International Phonetic Alphabet) transcription for "alum" is /ˈæl.əm/. 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 "alum"?
From Middle English alum, alum, alym, alyme, from Anglo-Norman alum, alun, from Latin alūmen. 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 "alum", not the corpus desk frequency band.

Same letter count

Frequency-ranked English headwords with 4 letters (nearest by frequency rank).

anus#20,835ahem#20,828balm#20,852Urdu#20,807

Similar misspelling depth

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

bona5 variantsbony5 variantsemit5 variantsquay5 variants

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

Source: FrequencyWords open word-frequency list