Difference between Alum and Alumnus

ALUM vs ALUMNUS: NOUN

A graduate of a university or other institution.
A double sulphate formed of aluminium and some other element (esp. an alkali metal) or of aluminium. It has twenty-four molecules of water of crystallization.
The general name of a class of double sulphates formed by the union of aluminium, iron, chromium, or manganese sulphate with the sulphate of some other metal, commonly an alkaline metal or ammonium.
A person who has received a degree from a school (high school or college or university)
A white crystalline double sulfate of aluminum: the potassium double sulfate of aluminum
A double sulphate of aluminum and potassium that is used as an astringent (among other things)

A graduate
A student
A male graduate
A male pupil or student
A pupil; especially, a graduate of a college or other seminary of learning.
A pupil; one educated at a school, seminary, college, or university; specifically, a graduate of any such institution.
A male graduate or former student of a school, college, or university.
A person who has received a degree from a school (high school or college or university)

To steep in, or otherwise impregnate with, a solution of alum; to treat with alum.

Start, Styptic, Whey, Cochineal, Hematoxylin, Astringent, Former, Potash alum, Ammonium alum, Ammonia alum, Potassium alum, Graduate, Alumna, Grad, Alumnus

Dean, Honorary degree, Professor, Undergraduate, Faculty, Learner, Pupil, Schoolmate, Former, Classmate, Student, Graduate, Grad, Alumna, Alum

Haematoxylin, Carmine, Start, Styptic, Whey, Cochineal, Hematoxylin, Astringent, Former, Potash alum, Potassium alum, Graduate, Alumna, Grad, Alumnus

Dean, Honorary degree, Professor, Undergraduate, Faculty, Learner, Pupil, Schoolmate, Former, Classmate, Student, Graduate, Grad, Alumna, Alum

Mourners paid tribute to slain alum Michelle Le.
Chrome alum crystals are deep purple in color.
Alum Rock in San Jose, and First Bakersfield.
Alum Hematoxylin can be used progressively or regressively.
Skype interview with an admissions rep or alum.
COY school alum to send letter of support.
The Alum chooses a date and clicks submit.
To make an alum crystal, you need water, alum, nylon fishing line, a popsicle stick, two clean jars, a spoon and paper towels.
Alum offers another example: natural alum, gathered from volcanic fumaroles, in particular on the island of Lipari, was traded in amphorae for centuries.
The anhydrous alum is known as burnt alum.

Riverside High School names Alumnus of the Year.
Ticket Manager and a USM sport management alumnus.
West Virginia University School of Medicine Distinguished Alumnus.
An alumnus of Wharton Business School, Philadelphia, USA.
Mineola baseball alumnus works Better Hearing Starts here.
Fort Lewis College alumnus; husband of Catherine Conrad.
Manasa is an Asian College of Journalism Alumnus.
Awards from this endowment will be awarded first to an alumnus of Chadron Prep School or a direct descendent of a Chadron Prep alumnus.
Hench is glad that Jefferson Medical College alumnus Tocantins will represent the school at the Camp Lazear dedication, honoring fellow alumnus Finlay.
So said the alumnus who nominated Mary Workman to receive the Honorary Alumnus Award.