A more thorough explanation:

Definition: Legal custom is a practice that has become so common and long-standing that it is considered to have the force of law. It can operate as a binding rule of law, independently of any agreement on the part of those subject to it.

For example, in some countries, it is customary for people to drive on the left side of the road. This custom has become so ingrained in the culture that it is now a legal requirement. Another example is the custom of shaking hands when greeting someone. While not a legal requirement, it is a widely accepted practice that has become a social norm.

Legal custom can be distinguished from other types of custom, such as conventional custom, which operates indirectly through agreements between parties, and general custom, which prevails throughout a country and constitutes one of the sources of the law of the land.

Example: In some parts of the world, it is customary for families to pay a dowry when their daughter gets married. This custom has become so entrenched in the culture that it is now considered a legal requirement. However, in other parts of the world, this practice is illegal and considered a form of discrimination against women.

This example illustrates how legal custom can vary from one culture to another and how it can have different legal implications depending on the context.