alum
/ˈæl.əm/
"alum" is a 4-letter English headword indexed on PlainSpell.
The verdict
“alum” is a moderately-common English word, ranked #20,832 in English word frequency and used as a noun.
- #20,832
- frequency rank, English
- 4
- letters
- 5
- tracked misspellings
- 20
- confusable pairs
According to Wiktionary data (CC BY-SA, analyzed May 6, 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...
Visual similarity to commonly confused words
How many letter changes separate each confused pair (Levenshtein distance, normalized).
Source: PlainSpell confusable corpus (Wiktionary, CC BY-SA).
| Property | Value |
|---|---|
| Headword | alum |
| Language | English |
| Part of speech | Noun |
| IPA | /ˈæl.əm/ |
| Letters | 4 |
| Frequency rank | #20,832 |
| Misspellings tracked | 5 |
| Confusable pairs | 20 |
| Source | Wiktionary (kaikki.org) |
Where “alum” sits in English frequency
Spelling & Dictionary Insight
The English entry for alum is 4 letters long, classified as a noun, and transcribed in the International Phonetic Alphabet as /ˈæl.əm/. Corpus data places it at rank #20,832 in overall English word frequency, marking it as uncommon enough that many writers pause before typing it. Wiktionary records 2 distinct senses for this headword, so context determines which meaning a reader should apply.
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
- 1An 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).
- 2Any similar double sulphate in which either or both of the potassium and aluminium is wholly or partly replaced by other univalent or tervalent cations.
Etymology
From Middle English alum, alum, alym, alyme, from Anglo-Norman alum, alun, from Latin alūmen.
Synonyms
This word in other languages
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.
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
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Using “alum”
The practical upshot for anyone who landed here from a spell-check.
- The one correct English spelling is A-L-U-M - every other letter order is a misspelling in standard orthography.
- Say it as /ˈæl.əm/ (IPA); tap the speaker on the pronunciation badge to hear it where audio exists.
- Don't mix it up with “AM” - see the side-by-side comparison. alum vs AM
- Browse more English words and confusable pairs in the same reference. English words
Data Source
Wiktionary (via kaikki.org), licensed under CC BY-SA & GFDL. Word ordering uses an open word-frequency list; misspelling variants are generated by edit-distance from the correct headword.