alum

¹al·um

noun \ˈa-ləm\

Definition of ALUM

1

: a potassium aluminum sulfate KAl(SO₄)₂·12H₂O or an ammonium aluminum sulfate NH₄Al(SO₄)₂·12H₂O used especially as an emetic and as an astringent and styptic

2

: any of various double salts isomorphous with potassium aluminum sulfate

3

: aluminum sulfate

Origin of ALUM

Middle English, from Anglo-French alum, alun, from Latin alumen

First Known Use: 14th century

Other Chemical Engineering Terms

alkali, cation, decant, hygroscopic, isotope, oxidize, slurry, solute, viscous

Rhymes with ALUM

aplomb, bass drum, bay rum, beach plum, become, benumb, degum, dim sum, dumdum, dum-dum, eardrum, far from, green thumb, hail from, ho-hum, how come, humdrum, income, in sum, outcome, pond scum, side drum, snare drum, sour gum, steel drum, subgum, succumb, sweet gum, therefrom, to come, Tom Thumb, tom-tom, wherefrom, yum-yum

²alum

noun \ə-ˈləm\

Definition of ALUM

: alumnus, alumna

Origin of ALUM

by shortening

First Known Use: 1910

Other Education Terms

baccalaureate, colloquium, corequisite, dissertation, monograph, pedant, practicum, survey course, thesis

³alum

abbreviation

Definition of ALUM

aluminum

Other Chemical Engineering Terms

alkali, cation, decant, hygroscopic, isotope, oxidize, slurry, solute, viscous

al·um

noun \ˈal-əm\   (Medical Dictionary)

Medical Definition of ALUM

1

: either of two colorless or white crystalline double sulfates of aluminum used in medicine internally as emetics and locally as astringents and styptics: a : one KAl(SO₄)₂·12H₂O that is a sulfate of aluminum and potassium—called also potassium alum b : one consisting of an ammonium aluminum sulfate NH₄Al(SO₄)₂·12H₂O—called also ammonia alum, ammonium alum

2

: any of various double salts isomorphous with potassium aluminum sulfate

alum

noun    (Concise Encyclopedia)

Inorganic compound, any of a class of hydrated double salts, usually consisting of aluminum sulfate, water of hydration (an essential part of the crystal makeup), and the sulfate of another element. The most important alums are those of potassium sulfate (potassium alum, or potash alum, KSOAl(SO)24HO), ammonium sulfate, and sodium sulfate. Alums occur naturally in various minerals and can be prepared and purified by crystallization from their solutions. Most are white crystals with an astringent, acid taste. They are used as paper-sizing agents, flocculating agents in water treatment, mordants in dyeing, and in pickles, baking powder, fire extinguishers, and medicines.