alum

1 of 3

noun (1)

al·​um ˈa-ləm How to pronounce alum (audio)
1
: a potassium aluminum sulfate KAl(SO4)2·12H2O or an ammonium aluminum sulfate NH4Al(SO4)2·12H2O used especially for its astringent and styptic properties
2
: any of various double salts isomorphous with potassium aluminum sulfate
3

alum

2 of 3

noun (2)

: alumnus, alumna
a Yale alum

alum

3 of 3

abbreviation

Did you know?

Is it acceptable to use alum for alumnus or alumna?

The words that we have used to refer to people who have attended or graduated from a school, college, or university have changed a bit over the past several centuries. Traditionally, the word alumnus has been used to refer to a single male, whereas alumna has been used for a single woman. Initially the plural forms were alumni to refer to multiple men (or multiple men and women) and alumnae for multiple women. A little over a hundred years ago the shortened form of alum began to be used to describe a graduate or past attendee of either gender. Although many people feel that alum is informal, it is in increasing use, and we appear to be moving toward a greater acceptance of the word. The plural of alum is alums.

Examples of alum in a Sentence

Recent Examples on the Web
Noun
But the exec, who is also president of the Society of Motion Picture and Television Engineers and a Warner Bros. alum, was not suggesting that humans are not essential. Carolyn Giardina, Variety, 18 May 2024 In the clip, the High School Musical: The Musical: The Series alum shoots the single artwork for The Golden Years‘ title track, which also dropped Friday. Hannah Dailey, Billboard, 17 May 2024 The Reba alum briefly stepped in last year after Shelton made his exit from the NBC singing competition series after 23 seasons. Angel Saunders, Peoplemag, 17 May 2024 Still, basking in the applause were Lanthimos and Stone, fellow Poor Things alums Willem Dafoe and Margaret Qualley, plus Jesse Plemons, Mamoudou Athie, Hong Chau, Joe Alwyn and Hunter Schafer. Chris Gardner, The Hollywood Reporter, 17 May 2024 For more details about the gathering May 20 of PSA and Post 1011 alums along with alums from Posts 727 and 737 which were aimed at flight attendants and mechanics and to share your memories of working at PSA, email gmacuna57@gmail.com. Linda McIntosh, San Diego Union-Tribune, 16 May 2024 Garrison Brown dies:Son of 'Sister Wives' stars Janelle and Kody Brown was 25 Garrison Brown's parents, brother pay tribute to 'Sister Wives' alum following death Brown's parents, Janelle and Kody Brown, mourned the loss of their son in a pair of emotional Instagram posts. Edward Segarra, USA TODAY, 16 May 2024 The actress, 48, is the latest Nickelodeon alum to accuse Schneider, 58, of inappropriate behavior, misusing his position of power, and fostering a toxic workplace environment. EW.com, 14 May 2024 Reba will be the only current Coach returning in Season 26 and—big news—will be joined by none other than Voice alum and three-time Grammy winner Gwen Stefani. Abigail Wilt, Southern Living, 14 May 2024

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'alum.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

Etymology

Noun (1)

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

Noun (2)

by shortening

First Known Use

Noun (1)

14th century, in the meaning defined at sense 1

Noun (2)

1877, in the meaning defined above

Time Traveler
The first known use of alum was in the 14th century

Dictionary Entries Near alum

Cite this Entry

“Alum.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/alum. Accessed 20 May. 2024.

Kids Definition

alum

noun
al·​um
ˈal-əm
1
: either of two colorless crystalline compounds containing aluminum that are used in medicine (as to check local sweating or to stop bleeding)
2

Medical Definition

alum

noun
al·​um ˈal-əm How to pronounce alum (audio)
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

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