Demonology (noun)

1. The study of demons or evil spirits, especially within a religious or supernatural context.
2. The branch of theology that deals with evil spirits, or demons.

Origin:

From the greek word daimon (demon) and -logy (study of).

Examples:

1. He was an expert in demonology and had written several books on the subject.
2. The medieval grimoires were filled with information on demonology and ritual magic.
3. Demonology is the study of demons and evil spirits, including their origins and activities.
4. The demonology class was focused on the study of different beliefs and practices related to evil spirits.
5. He was interested in demonology and had a large collection of books on the subject.