mi·nor 
(mīnər)
(mīnər)adj.
1. Lesser or smaller in amount, extent, or size.
2. Lesser in importance, rank, or stature: a minor politician.
3. Lesser in seriousness or danger: a minor injury.
4. Law Not having reached legal adulthood.
5. Chiefly British Relating to or being the younger or junior of two pupils with the same surname.
6. Of or relating to a secondary area of academic specialization.
7. Logic Dealing with a more restricted category.
8. Music
a. Relating to or being a minor scale.
b. Less in distance by a half step than the corresponding major interval.
c. Based on a minor scale: a minor key.
n.
1. One that is lesser in comparison with others of the same class.
2. Law One who has not reached legal adulthood.
3.
a. A secondary area of specialized academic study, requiring fewer courses or credits than a major.
b. One studying in a secondary area of specialization: She is a physics minor.
4. Logic
a. A minor premise.
b. A minor term.
5. Music A minor key, scale, or interval.
6. minors Sports The minor leagues of a sport, especially baseball.
intr.v. mi·nored, mi·nor·ing, mi·nors
To pursue academic studies in a minor field: minored in music.
[Middle English minour, from Old French menour and from Latin minor (Old French, from Latin); see mei-2 in the Appendix of Indo-European roots.]