A Minor is a secondary area of study. The subject of a Minor is not studied as extensively as the subject of one's major. Knox offers 51 minors.
A minor is also someone who is not of legal age. Regarding the purchase and consumption of alcohol, a person is a minor until the age of 21. For most other things, a person is a minor until the age of 18.
Regarding drugs, you are always a minor or studying abroad in Holland.