A more thorough explanation:

Definition: Infidel (in-fə-dəl) refers to a person who does not believe in a particular religion or violates a feudal oath of fealty.

• He was considered an infidel by the members of the church because he did not believe in God.
• The knight was labeled an infidel after he broke his oath of loyalty to the king.

The first example illustrates the first definition of infidel, where a person is considered an infidel if they do not believe in a particular religion. In this case, the person does not believe in God, which goes against the beliefs of the church.

The second example illustrates the historical definition of infidel, where a person who violates a feudal oath of fealty is considered an infidel. In this case, the knight broke his promise to be loyal to the king, which was a serious offense during feudal times.