Definitions

from The American Heritage® Dictionary of the English Language, 4th Edition

  • n. Any of various double sulfates of a trivalent metal such as aluminum, chromium, or iron and a univalent metal such as potassium or sodium, especially aluminum potassium sulfate, AlK(SO4)2·12H2O, widely used in industry as clarifiers, hardeners, and purifiers and medicinally as topical astringents and styptics.
  • n. Informal An alumna or alumnus.

from Wiktionary, Creative Commons Attribution/Share-Alike License

  • v. To steep in, or otherwise impregnate with, a solution of alum; to treat with alum.
  • n. A graduate of a university or other institution.

from the GNU version of the Collaborative International Dictionary of English

  • n. A double sulphate formed of aluminium and some other element (esp. an alkali metal) or of aluminium. It has twenty-four molecules of water of crystallization.
  • transitive v. To steep in, or otherwise impregnate with, a solution of alum; to treat with alum.

from The Century Dictionary and Cyclopedia

  • n. The general name of a class of double sulphates formed by the union of aluminium, iron, chromium, or manganese sulphate with the sulphate of some other metal, commonly an alkaline metal or ammonium.
  • To steep in or impregnate with a solution of alum.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • n. a white crystalline double sulfate of aluminum: the ammonium double sulfate of aluminum
  • n. a double sulphate of aluminum and potassium that is used as an astringent (among other things)
  • n. a white crystalline double sulfate of aluminum: the potassium double sulfate of aluminum
  • n. a person who has received a degree from a school (high school or college or university)

Etymologies

Middle English, from Old French, from Latin alūmen.
(American Heritage® Dictionary of the English Language, Fourth Edition)
From Anglo-Norman alum, alume et al., Middle French allume, from Latin alūmen ("alumen"). (Wiktionary)
From alumnus and alumna, by removal of the non-native, gender-specific endings. (Wiktionary)

Examples

Comments

Log in or sign up to get involved in the conversation. It's quick and easy.

  • Adds a whole new meaning to alum-are-us. These
    are fields to be explored.

    April 25, 2013

  • "Alum has been used at least since Roman times for purification of drinking water and industrial process water. Between 30 and 40 ppm of alum for household wastewater, often more for industrial wastewater, is added to the water so that the negatively charged colloidal particles clump together into "flocs", which then float to the top of the liquid, settle to the bottom of the liquid, or can be more easily filtered from the liquid, prior to further filtration and disinfection of the water."

    -- Wikipedia (http://en.wikipedia.org/w/index.php?title=Alum&oldid=551044797)

    April 24, 2013