alum
/ˈæl.əm/
Word Rarity
Rare
Frequency: 3.25 in modern English
6
Scrabble Score
4
Letters
2
Syllables
4
Unique Chars
Meaning
noun
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).
Countable; Uncountable
noun
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.
Countable; Uncountable
verb
To steep in, or otherwise impregnate with, a solution of alum; to treat with alum.
Transitive verb
noun
A past attendee or graduate (of any gender) of a college, university or other educational institution.
Canadian usage; American usage
Example Sentences
- "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."
- "A natural astringent and antiseptic, potassium alum was coveted for its medicinal and cosmetic properties."
- "With weld and cochineal, which are colouring matters the most sensible to the action of sulphate of iron, the purified alums gave us colours more brilliant, fresh, and in a slight degree lighter; while those with our common alums were all duller, and evidently of a deeper hue."
- "For similar reasons, aluminium sulphate and alums are used in dyeing cloth.[…]Normally alums are soluble in water and insoluble in alcohols."
- "In structure, the alums consist of simple ions, being not complexes, but double salts. Potash alum or potassium alum is the common alum, with the formula KAl(SO₄)₂·12H₂O) which, for convenience, may be written K₂SO₄·Al₂(SO₄)₃·24H₂O"
- "The silk should be boiled at the rate of 20 parts of soap per cent. , and then alumed. The aluming need not be so strong as for the fine crimson"
Etymology
Etymology tree Proto-Indo-European *h₂elut- Proto-Indo-European *-mn̥ Proto-Italic *-mn̥ Latin -men Latin alūmen Anglo-Norman alum, alunbor. Middle English alym, alyme, alum English alum From Middle English alum, alym, alyme, from Anglo-Norman alum, alun, from Latin alūmen.
Origin
Word Breakdown
- Root: alum, alūmen
Usage
- Countable
- Uncountable
- Transitive verb
- Canadian usage
- American usage