Synonyms/Hypernyms (Ordered by Estimated Frequency) of noun alum

4 senses of alum

Sense 1
alum, ammonia alum, ammonium alum -- (a white crystalline double sulfate of aluminum: the ammonium double sulfate of aluminum)
       => aluminum, aluminium, Al, atomic number 13 -- (a silvery ductile metallic element found primarily in bauxite)
       => double salt -- (a solution of two simple salts that forms a single substance on crystallization)

Sense 2
alum, potassium alum, potash alum -- (a white crystalline double sulfate of aluminum: the potassium double sulfate of aluminum)
       => aluminum, aluminium, Al, atomic number 13 -- (a silvery ductile metallic element found primarily in bauxite)
       => double salt -- (a solution of two simple salts that forms a single substance on crystallization)

Sense 3
alumnus, alumna, alum, graduate, grad -- (a person who has received a degree from a school (high school or college or university))
       => scholar, scholarly person, bookman, student -- (a learned person (especially in the humanities); someone who by long study has gained mastery in one or more disciplines)

Sense 4
alum -- (a double sulphate of aluminum and potassium that is used as an astringent (among other things))
       => astringent, astringent drug, styptic -- (a drug that causes contraction of body tissues and canals)