Dictionary
Thesaurus
Encyclopedia
Translator
Web

alum

 - 9 dictionary results

al⋅um

1[al-uhm]
–noun Chemistry.
1. Also called potash alum, potassium alum. a crystalline solid, aluminum potassium sulfate, K2SO4·Al2(SO4)3·24H2O, used in medicine as an astringent and styptic, in dyeing and tanning, and in many technical processes.
2. one of a class of double sulfates analogous to the potassium alum, as aluminum ammonium sulfate, having the general formula R2SO4·X2(SO4)3·24H2O, where R is a univalent alkali metal or ammonium, and X one of a number of trivalent metals.
3. (not in technical use) aluminum sulfate.

Origin:
1275–1325; ME < AF < L alūmen; r. OE alefne, ælifnæ < OWelsh (cf. MWelsh elyf) < L alūmini- (s. of alūmen)

a⋅lum

2[uh-luhm]
–noun Informal.
an alumna or alumnus.

Origin:
by shortening

alum.

Chemistry.
aluminum.
Dictionary.com Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2009.
Cite This Source Link To alum
al·um 1   (āl'əm)   
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 hydrous aluminum potassium sulfate, AlK(SO4)2·12H2O, widely used in industry as clarifiers, hardeners, and purifiers and medicinally as topical astringents and styptics.

[Middle English, from Old French, from Latin alūmen.]
a·lum 2   (ə-lŭm')   
n.   Informal
An alumna or alumnus.
The American Heritage® Dictionary of the English Language, Fourth Edition
Copyright © 2009 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.
Cite This Source
Word Origin & History

alum 
c.1325, "whitish mineral salt used as an astringent, dye, etc.," from O.Fr. alum, from L. alumen "alum," lit. "bitter salt," cognate with Gk. aludoimos "bitter" and Eng. ale.
Online Etymology Dictionary, © 2001 Douglas Harper
Cite This Source
Medical Dictionary

Main Entry: al·um
Pronunciation: 'al-&m
Function: noun
1 : either of two colorless or white crystalline double sulfates of aluminum usedin medicine internally as emetics and locally as astringents and styptics: a : one KAl(SO4)2·12H2O that is a sulfate of aluminum and potassiumcalled also potassium alum b : one consisting of an ammonium aluminum sulfate NH4Al(SO4)2·12H2O called also ammoniaalum, ammonium alum
2 : any of various double salts isomorphous with potassium aluminum sulfate
Merriam-Webster's Medical Dictionary, © 2002 Merriam-Webster, Inc.
Cite This Source
Medical Dictionary

alum al·um (āl'əm)
n.
Any of various double sulfates of a trivalent metal such as aluminum or iron and a univalent metal such as potassium or sodium that are used as topical astringents and styptics.

The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
Cite This Source
Abbreviations & Acronyms
alum
  1. alumna

  2. alumnae

  3. alumni

  4. alumnus

The American Heritage® Abbreviations Dictionary, Third Edition
Copyright © 2005 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.
Cite This Source
Search another word or see alum on Thesaurus | Reference
FacebookTwitterFollow us: