A more thorough explanation:

Definition: Infidelis (in-fi-dee-lis or -del-is) is a Latin word that has two historical meanings:

1. Someone who does not believe in a particular religion or who holds beliefs that are different from the majority of people in their community.
2. Someone who is unfaithful or disloyal to their spouse or partner.

Examples:

• During the Middle Ages, Christians often referred to Muslims as infidels because they did not believe in Jesus Christ as the son of God.
• Infidelity is a common cause of divorce in many countries around the world.

The first example illustrates the first meaning of infidelis, which refers to someone who does not believe in a particular religion. In this case, Christians used the term to describe Muslims who held different religious beliefs. The second example illustrates the second meaning of infidelis, which refers to someone who is unfaithful or disloyal to their partner. In this case, infidelity is a common cause of divorce, which means that one or both partners have been unfaithful to each other.