alum

Someone who previously studied at a particular school, college, or university.

• My sister is a college alum.
• Several alums returned to campus for the reunion.
• Are you an alum of this university?

How to use it: an alum of something (She is an alum of the local college.)

Similar words: former student, alumnus, alumna

Common phrases: a college alum, a university alum, a fellow alum

A pale crystal salt used to treat leather, fix colors in cloth, and in some medicines.

• Dissolve the alum in warm water.
• The dyer added alum to help the color stay in the wool.
• Small alum crystals formed at the bottom of the jar.

Similar words: potassium alum

Common phrases: potassium alum, alum crystals, alum powder

Any of a group of crystal salts with a chemical structure similar to the common potassium and aluminium salt.

• The laboratory stores several kinds of alum.
• Ammonium alum forms clear crystals.
• Chrome alum contains chromium in place of aluminium.

Common phrases: ammonium alum, chrome alum, an alum crystal

To soak or treat something with a particular crystal salt, often before coloring cloth.

• First, alum the wool.
• The workers alumed the cloth before dyeing it.
• She alums each piece of fabric in a warm solution.

Common phrases: alum the wool, alum the cloth, alum before dyeing