Age of majority is a legal definition that means that a person is legally an adult, and responsible for the majority of his or her actions. No one can be held legally responsible for all of their actions - for example, getting sick or dying is out of all of our hands. Therefore, the law considers us responsible only for the majority of our actions.
This term is directly related to one that is more familiar. Most of us recognize "minors" as another word for children. Legally, the term "minor" indicates that a person is still in the "age of minority" which means that he or she is only legally responsible for the minority of actions. The parents or legal guardians are responsible for the majority of children's actions.
So basically, if a sweepstakes restricts entry based on age of majority, it means that you have to be considered an adult where you live. To find out when you are legally considered to be an adult, check out: