A quick definition of alieni juris:

Term: ALIENI JURIS

Definition: Alieni juris means that someone is under the control or authority of another person. It comes from Roman law and is also known as alieni iuris. It is often used to describe someone who is not yet an adult and is still under the control of their parents or guardians. Another way to think of it is like being a child and having to follow the rules set by your parents or teachers.

Example: A 16-year-old is considered alieni juris because they are not yet an adult and are still under the control of their parents. They cannot make certain decisions on their own, such as signing a legal contract or getting married without their parents' permission.