1 a : not very important or valuable
▪ a minor artist/author/celebrity ▪ Her role in the project was minor. ▪ a minor component/part ▪ I'm not worried about minor details. ▪ a minor news story ▪ minor characters ▪ Doctors described her recovery as a minor miracle. [=her health was very bad and doctors were not sure if she would recover]
b always used before a noun : small in number, quantity, or extent
▪ The grant covered only a minor part of the cost. 2 : not very serious : not causing much trouble or damage
▪ a minor illness/injury/setback ▪ The delay will be minor. ▪ a very minor annoyance/accident ▪ a minor earthquake ▪ minor errors/mistakes ▪ He suffered a minor heart attack. 3 music a : having semitones between the second and third, the fifth and sixth, and sometimes the seventh and eighth notes in a scale
▪ a minor scale
b : based on a minor scale
▪ a minor key — compare ¹major 3 4 always used before a noun : not yet old enough to have the rights of an adult
▪ He has minor children living in the house.