alum

Noun

• a double sulphate of aluminum and potassium that is used as an astringent (among other things)

• 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 white crystalline double sulfate of aluminum: the ammonium double sulfate of aluminum

Related words

• Synonyms: 
  alumnus , alumna , graduate , grad , potassium alum , potash alum , ammonia alum , ammonium alum