Alum vs alum

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Alum and alum  are two words that are spelled identically but are pronounced differently and have different meanings, which makes them heteronyms. We will examine the definitions of the words alum and alum, where these words came from, and a few examples of their use in sentences.

Alum (AL-um) is aluminium potassium sulfate, a chemical. Alum is used to enhance the taste of food and enhance its shelf life; purify water; in deodorants, for leather tanning, etc. Alum is found in the grocery store and is used for pickling foods. The word alum is derived from the Latin word, alumen, which means bitter salt.

Alum (uh LUM) is an American abbreviation that means alumna or alumnus. An alum is a former student of a high school, college or university.


People keep their underground tanks regularly cleaned at regular intervals and add alum twice weekly, and yet the amount of slime that piles up is unbelievable. (The News International)

Liquid aluminum sulfate — often referred to as “alum” in the trade — is a chemical agent that “grabs onto dirt and debris so that it’s settled out,” Calamita said. (Daily Press)

Amarillo Symphony to premiere work by WTAMU alum Christopher Garcia at weekend performances (Amarillo Globe-News)

Lee-Scott alum and Clemson senior Turk Pettit receives his award as the NCAA’s individual national champion on Monday at the Grayhawk Golf Club in Scottsdale, Arizona. (Opeklika Auburn News)