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alum - What does it mean?

Definition of 'alum'

English

(wikipedia)

Alternative forms

* alumn

Etymology 1

From (etyl) alum, (alume) et al. , (etyl) allume, from (etyl) .

Noun

(en-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).
  • * 1991 , Felix Gilbert, The Pope, His Banker, and Venice , page 80,
  • 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.
  • * 2011 , Thomas Penn, Winter King , Penguin 2012, p. 201:
  • A natural astringent and antiseptic, potassium alum was coveted for its medicinal and cosmetic properties.
  • (chemistry) 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.
  • * 1807 , William Nicholson (editor), A Journal of Natural Philosophy, Chemistry, and the Arts , Volume XVIII, page 286,
  • 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.
  • * 2000 June, Competition Science Vision , page 486,
  • For similar reasons, aluminium sulphate and alums' are used in dyeing cloth.Normally ' alums are soluble in water and insoluble in alcohols.
  • * 2005 , Amit Arora, Text Book Of Inorganic Chemistry , page 386,
  • 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
    Synonyms
    * (double sulphate of potassium and aluminum) potash alum
    Derived terms
    * alum cake * alum earth * alumed * alumina * aluming * alumish * alum mine * alumocalcite * alumogenite (rel-mid4) * alum rock * alum root * alum shale * alum stone * alum works * ammonia alum * burnt alum * cake alum * chrome alum (rel-mid4) * chrome-ammonia alum * common alum * feather alum * filter alum * iron alum * magnesia alum * manganese alum * manganoso-magnesium alum (rel-mid4) * native alum * papermaker's alum * plume alum * potash alum * pseudo alum * Roman alum * saccharine alum * silver alum * soda alum (rel-bottom)

    Verb

    (en-verb)
  • To steep in, or otherwise impregnate with, a solution of alum; to treat with alum.
  • (Ure)
    Derived terms
    * unalumed

    Etymology 2

    From alumnus and alumna, by removal of the non-native, gender-specific endings.

    Noun

    (en-noun)
  • (US) A graduate of a university or other institution.
  • * 1961 Spring, Anchora of Delta Gamma , Volume LXXVII, No. 3, page 59,
  • Evanston-North Shore' ' alums are happy to open their homes to Sigma actives for special social events.
  • * 2006 , Ted Hart, James M. Greenfield, Pamela M. Gignac, Christopher Carnie, Major Donors: Finding Big Gifts in Your Database and Online , page 47,
  • You'll remember that we're starting with a list of slightly over 7,000 names that are alums (most of them over 50) that we'd like to whittle down to a manageable list of prospects.
  • * 2009 , Timothy C. Jacobson, Charity & Merit: Trinity School at 300 , page 190,
  • All schools that last have alums , and, ancient as it was by American standards, Trinity by mid-century had thousands.

    See also

    * apjohnite * bosjemanite * halotrichite * kalinite * websterite

    Anagrams

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    Similar to 'alum'

    alim